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Light Vs Heavy rifle

Peepaw

Private
Full Member
Minuteman
Feb 6, 2010
72
1
51
Pearland, TX USA
First of all, wasnt sure where I needed to put this thread, so if mods need to move it, my apologies.


My question goes to the following:

I was always told that a lighter rifle, will kick harder, than a heavier rifle (caliber being same). The theory behind it sounds reasonable, and believable. So, with bench rest/prone shooting, would want a heavier rifle, so you can cut down on felt recoil.

So, I've been shooting my .308 (@ 8 1/2 lbs without scope/base/rings/ammo) for awhile now and it's pretty good thumper. After 40 or so rounds of it, I can start to feel shoulder barking. One would also say, that for a typical .308, that 8 1/2 lbs would be considered pretty heavy. Got to figure with scope and ammo, would go between 10 and 11 Lbs.

So, I picked up a 7MM Rem Mag, and it's a light setup..rifle weighs less than 6 1/2 lbs. I was told, that it was gonna kick harder than my .308

Took to range, and I was pleasantly surprised that it wasnt as bad as I thought it would be (does have some pretty serious muzzle jump) In fact, after 40 rounds, my shoulder felt fine. So after 60+, I ran out and felt I couldve gone 40, 50, whatever more as my shoulder still felt fine.


Now, I know the 7MM Rem mag creates more energy and velocity than my .308 and it's SUPPOSED to hit harder. I am here to tell you, that my shoulder says otherwise. I even went BACK to the range with both guns to give it another go, and same thing. Shoulder starts to bark with .308 and it's fine with my 7MM Rem Mag.


Ok, so last night I got to thinking WHY is that? If 7MM creates/produces more energy/velocity with same weight bullet (I shoot 150 and 175 grain with 7MM and 150 and 168's with my .308), why would the .308 hit me harder than that rifle AND the .308 weigh more.

Then it hit me (no pun intended):If say I swung a stick (light rifle) at "X" speed, and hit myself with it, it would not hurt as much if I took a bat (heavy rifle) and swung at same or even slower speed. The bat (heavier rifle) would hurt more.


So I thought more and more about it, and while I know the theory is heavier rifle is harder to move, so won't kick as hard as teh light rifle. But, if you have enough energy to move that heavy rifle, the heavier rifle SHOULD kick harder than the lighter one.

What I am getting at is, would you rather have a lighter "stick" hit you, or a heavier one, swung at same speed/velocity? The lighter one off course.

So, why is teh theory that the heavier rifle is the one that wont kick as hard? Has someone actually setup a test and done this to get ACTUAL results, and not just a "feeling" like I have?



I understand that if you take a REAL heavy object (let's exaggerate) and say rifle weighs 100 Lbs and it's a .308, it won't kick (if at all any) as bad as say one that weighs 8 Lbs. Because the actual energy from the .308 isnt enough to actually move that 100 Lb rifle. Kind of like putting a 1 cylinder lawnmower motor in a Motorhome.

But, talking about at the weight's we are normally dealing with, 6, 7, 9, 10 lbs, these rifles have enough energy to move them, and I would THINK that the heavier rifle would hit harder than the lighter one.

Speaking of Motorhome..think of a Motorhome hitting you at 30 MPH, then a car hitting you at 30 MPH. What's gonna do more damage? The heavier object because it's carrying more mass. So, stands to reason the heavier rifle is carrying more mass, so will hit harder.


Anyways, I was just curious as to if an actual test has been done, and someone has ACTUAL results and not just someone that came up with this idea/theory and everyone since has just bought into it without actually thinking about it.



OK, Im ready for MY theory to be shot down in flames, so fire at will.


Also, let's eliminate the stock/pad. I even put a B&C on my .308 that has a pretty "comfy" pad on it, and the 7MM has stock stock on it. So, let's leave that part out, and talk about teh heavy vs light
 
Re: Light Vs Heavy rifle

Ligter is going to recoil faster than heavier for a given caliber. One thing that really needs to be kept in mind is that how a stock fits the shooter will have a tremendous effect on the percieved recoil. For me personaly a 94 winchester in 30-30 is far more uncomfortable to shoot than my .375 H&H with a steel butplate. This is simply due to to the fact that the stock on the 94 doesn't fit me worth a damn, but the stock on the 375 was carved to fit me like a glove.
 
Re: Light Vs Heavy rifle

I think Rhys hit the nail on the head, with gun fit being MOST important to the felt recoil equation. Mass(rifle&scope weight) x rearward velocity of the firearm @ firing = recoil on the shoulder. A heavier rifle, shooting the same projectile, SHOULD have less felt recoil. However, if the stock is poorly fitted, too long/short too high a comb etc., all bets are off. I even had to look up the formulas, because physics was umpteen years ago.

Personally, I've had great results with a limbsaver slip on recoil pad. Yes, it lengthens the LOP a bit, but for me they work! Try one...several of my rifles wear them.
wink.gif
 
Re: Light Vs Heavy rifle

Personal experience: Weatherby Mark V in 300 Win Mag. I upgraded the stock to a B&C Varmint and kept it that way for about eight months until it was re-barreled with an MTU taper barrel. The load I shot the most was a 200 gr Sierra Matchking running about 2980 fps. Before re-barreling I would notice both my shoulder and neck feeling pretty bad after about 50 rounds. After the barrel was changed I could regularly shoot around 120 rounds and still feel fine, just running out of daylight by that time. Anyway that was my experience, so based off of that I am a believer in the heavier gun recoiling less.
 
Re: Light Vs Heavy rifle

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Rhys</div><div class="ubbcode-body">Ligter is going to recoil faster than heavier for a given caliber. One thing that really needs to be kept in mind is that how a stock fits the shooter will have a tremendous effect on the percieved recoil. For me personaly a 94 winchester in 30-30 is far more uncomfortable to shoot than my .375 H&H with a steel butplate. This is simply due to to the fact that the stock on the 94 doesn't fit me worth a damn, but the stock on the 375 was carved to fit me like a glove. </div></div>


I agree with everything you said, but jsut as I mentioned above:

Just because something is TRAVELING faster, doesnt mean its going to HIT you harder.

My example's are pretty darn close, with them BOTH being Rem 700's, and both stocks are darn near identical. Now, my .308 has a B&C on it, and is EXTREMELY comfortable and I love it, and if anything, I've noticed it doesnt hit nearly as hard as it did before I changed out stocks.

So, i KNOW that the stock has a good deal of how hard the rifle hits you.


Im talking PHYSICS. Again, with a lighter rifle, even though it recoils "faster", with less weight coming back, technically speaking, WONT hit as hard as a heavier object.


That's what I am getting at, as I am here to tell you that my .308 hits ALOT harder than my 7MM, and teh 7MM is a light rifle, so by what I ambeing told/reading, it SHOULD hit harder simply because it's a lighter rifle, AND a more powerful caliber on top of that.
BUt, it DOESNT.


Use this example (as an extreme): Take a your kids plastic toy baseball bat. Swing it as hard as you can, and hit your leg with it. Now, take a regular baseball bat, and just swing it lightly and hit your leg. Which one hit you harder? See what I mean? The HEAVIER bat hit you harder.

I know it sounds like Im being argumentative, but Im not. Im just trying to find out if anyone has any REAL test results on Lbs per square inch/force/etc..type of thing.
 
Re: Light Vs Heavy rifle

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Dibbs</div><div class="ubbcode-body">I think Rhys hit the nail on the head, with gun fit being MOST important to the felt recoil equation. Mass(rifle&scope weight) x rearward velocity of the firearm @ firing = recoil on the shoulder. A heavier rifle, shooting the same projectile, SHOULD have less felt recoil. However, if the stock is poorly fitted, too long/short too high a comb etc., all bets are off. I even had to look up the formulas, because physics was umpteen years ago.

Personally, I've had great results with a limbsaver slip on recoil pad. Yes, it lengthens the LOP a bit, but for me they work! Try one...several of my rifles wear them.
wink.gif
</div></div>


Do you know this for fact though? Or, just from what you have "read"? Again, if you REALLY think about it, the heavier object, with MORE mass coming back, should hit harder.

I'll use another example:

18 Wheeler/Big rig...traveling at 55MPH and hits a car

VW Beetle...traveling at 55MP and hits a car


Which of the 2 above is goignto do more damage?
 
Re: Light Vs Heavy rifle

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: kortik</div><div class="ubbcode-body">http://www.loadammo.com/Topics/August01.htm

Your rifle in 7 mm probably shoots lighter bullet
than .308. Another thing is how effective the recoil pad is
on each rifle.
</div></div>


Nope. Im shooting 150 and 168's with my .308 and Im shooting 150's and 175 with my 7MM. So, you could say, in the case of teh 175, Im shooting heavier bullet in my 7MM.
 
Re: Light Vs Heavy rifle

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: hewlett260</div><div class="ubbcode-body">Personal experience: Weatherby Mark V in 300 Win Mag. I upgraded the stock to a B&C Varmint and kept it that way for about eight months until it was re-barreled with an MTU taper barrel. The load I shot the most was a 200 gr Sierra Matchking running about 2980 fps. Before re-barreling I would notice both my shoulder and neck feeling pretty bad after about 50 rounds. After the barrel was changed I could regularly shoot around 120 rounds and still feel fine, just running out of daylight by that time. Anyway that was my experience, so based off of that I am a believer in the heavier gun recoiling less. </div></div>


Fair enough. In your case, you felt like that. I won't argue against that.



I'm just saying that I personally feel, taht from a PHYSICS standpoint, the heavier object is going to hit harder.

I keep thinking of the 18 wheeler VS vw beetler scenario, and really, that is a very good example. Why?


Well, let's say that I am talking about the SAME caliber, OK? Let's use my .308, and forget about the 7MM for a second.


OK, and let's even use teh same weight bullet so we can rule out other variables So, .308 shooting 150 grain.


OK, you've got a rifle that weighs 8 lbs (the 18 wheeler)
And, you ve got a rifle that weighs 6 lbs (VW beetle)

Both rifle's shooting teh SAME bullet (55MPH)

The 18 wheeler (8 LB rifle) hits a wall.

The VW beetle (6 lb rifle) hits a wall.


Out of those two, which vehicle/rifle does more damage? Heavier, or lighter vehicle/rifle?

See what I mean? You would THINK that the HEAVIER object is going to hit you harder. Now, I am using some common sense in that. Maybe some engineer can come along and tell me why those example's are bad, not valid. But, at this point in time, I have to think that the heavier rifle is going to hit harder, because physics is telling me so.

And since my experience at teh gun range is also telling me that my "gut feeling" is right, then its gonna take some serious, SOLID info to tell me that the lighter rifle will hit you harder. LOL!!!
 
Re: Light Vs Heavy rifle

Law of Physics.

Every action has an opposite and equal reaction.

If the bullet and rifle weighed the same they would both fly off in opposite directions. The weight of the rifle and absorbed recoil of the shooter is what keeps it(the rifle) from being a projectile itself.

a faster bullet (of the same weight) in a lighter rifle will kick faster (because the bullet is faster) and the shooter will absorb more recoil because the lighter rifle doesn't absorb as much recoil and more is passed to the shooter.

It is a physical law. If you feel that your heavier 308 kicks less than a 7mm mag it is because one of two things.

1. Stock fits you better and recoil pad is softer.
2. It's in your head and you have lost your objectivity.
 
Re: Light Vs Heavy rifle

Heavier....my .308 700P kicked like a mule with factory HS stock. uncomfortable as well. I'm running a McRee now which comes with an awesome recoil pad. It feels like a .22 now.

However, too heavy is a problem as well. Mine is 15 lbs.
 
Re: Light Vs Heavy rifle

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Swampbuck</div><div class="ubbcode-body">Law of Physics.

Every action has an opposite and equal reaction.

If the bullet and rifle weighed the same they would both fly off in opposite directions. The weight of the rifle and absorbed recoil of the shooter is what keeps it(the rifle) from being a projectile itself.

a faster bullet (of the same weight) in a lighter rifle will kick faster (because the bullet is faster) and the shooter will absorb more recoil because the lighter rifle doesn't absorb as much recoil and more is passed to the shooter.

It is a physical law. If you feel that your heavier 308 kicks less than a 7mm mag it is because one of two things.

1. Stock fits you better and recoil pad is softer.
2. It's in your head and you have lost your objectivity. </div></div>

Peepaw - Swampbuck has it right here. Equal and Opposite. Your original analogy is wrong. The question is not whether I'd rather be hit with a stick or a bat (both moving at the same speed), but whether I'd rather be hit with a bat moving 2 MPH or a stick moving 500 MPH (purposely overstated to illustrate the fact that the rearward momentum of your lightweight 7 Mag is much greater than the rearward momentum of your heavier, and less powerful, .308 Win). If you "feel" less recoil with the 7 Mag, it is because of one or more of the mitigating factors mentioned previously in this thread. Good "recoil chart" <span style="font-weight: bold"><span style="color: #3333FF">HERE</span></span>.
 
Re: Light Vs Heavy rifle


Recoil pad material is very import in how YOU feel recoil .

Shoot a old bolt action WWI or WWII rifle with a metal butt plate & tell me how that feels while wearing a t-shirt .
 
Re: Light Vs Heavy rifle

Mass of rifle multipied by the rifles velocity equals mass of bullet multiplied by muzzle velocity plus mass of powder multiplied by about 1.3 times muzzle velocity

the rifles velocity equals (mass of bullet multiplied by muzzle velocity plus mass of powder multiplied by about 1.3 times muzzle velocity) divided by mass of rifle

Rifles velocity squared multiplied by rifles mass divided by 2 equals recoil energy.

Sorry for this less than perfect writeup, but my cellphone sucks for this purpose.

ps: terminology
 
Re: Light Vs Heavy rifle

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Swampbuck</div><div class="ubbcode-body">Law of Physics.

Every action has an opposite and equal reaction.

If the bullet and rifle weighed the same they would both fly off in opposite directions. The weight of the rifle and absorbed recoil of the shooter is what keeps it(the rifle) from being a projectile itself.

a faster bullet (of the same weight) in a lighter rifle will kick faster (because the bullet is faster) and the shooter will absorb more recoil because the lighter rifle doesn't absorb as much recoil and more is passed to the shooter.

It is a physical law. If you feel that your heavier 308 kicks less than a 7mm mag it is because one of two things.

1. Stock fits you better and recoil pad is softer.
2. It's in your head and you have lost your objectivity. </div></div>


OK, NOW we are getting into more of "physics" info as oppsoed to "gut feelings", and in doign so, starting to see what the theory is about. Im still not 100% sold, but my view is is becoming more "open". OK, Im listening...

As far as your 1 and 2. Well, (1), that can't be it because as I mentioned above, teh stocks were essentially teh same. Then, I swapped over to the B&C on my .308, and it has a nice real comfy butt pad. The stock fits very very very well. I'ts perfect. and
(2)it's not in my head, it's in my shoulder, LOL!!


Thanks
cool.gif
 
Re: Light Vs Heavy rifle

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Scoop</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Swampbuck</div><div class="ubbcode-body">Law of Physics.

Every action has an opposite and equal reaction.

If the bullet and rifle weighed the same they would both fly off in opposite directions. The weight of the rifle and absorbed recoil of the shooter is what keeps it(the rifle) from being a projectile itself.

a faster bullet (of the same weight) in a lighter rifle will kick faster (because the bullet is faster) and the shooter will absorb more recoil because the lighter rifle doesn't absorb as much recoil and more is passed to the shooter.

It is a physical law. If you feel that your heavier 308 kicks less than a 7mm mag it is because one of two things.

1. Stock fits you better and recoil pad is softer.
2. It's in your head and you have lost your objectivity. </div></div>

Peepaw - Swampbuck has it right here. Equal and Opposite. Your original analogy is wrong. The question is not whether I'd rather be hit with a stick or a bat (both moving at the same speed), but whether I'd rather be hit with a bat moving 2 MPH or a stick moving 500 MPH (purposely overstated to illustrate the fact that the rearward momentum of your lightweight 7 Mag is much greater than the rearward momentum of your heavier, and less powerful, .308 Win). If you "feel" less recoil with the 7 Mag, it is because of one or more of the mitigating factors mentioned previously in this thread. Good "recoil chart" <span style="font-weight: bold"><span style="color: #3333FF">HERE</span></span>. </div></div>



Well, I think that teh 18 wheeler bug comparison is a rather good one myself, for the reasons below:

1)Both traveling same speed (bullet velocity/weight)
2)Wall they hit is "you" the shooter.
3)weight of each vehicle is the weight of each rifle. Heavier vehicle is carrying more mass, and in doing so, carries more energy., and in doing so, hits harder.


SO, let's back up and throw out the 7MM Vs .308 debate, and lets go with the .308 Vs. 308 debate


Same caliber in 2 differnt weight rifles.

Wait a minute./..be back....daughter is wanting to go swimming...gotta se whats up...


EDIT: Im back...ok

So, let's take .308 Vs 308...heavy Vs. light same concept/theory applies?


Trying to get this sink in...

I can see that teh faster bullet leaving in lighter rifle has more recoil, because it's more energy leaving the rifle, and in doing so, is pushing rifle back harder. HOWEVER, if all that energy is only pushing a "feather" than only oh so much damage can be done, correct?
 
Re: Light Vs Heavy rifle

something you didn't hit on is how the rifle fits you. the better it fits, the less felt recoil you will have to deal with and the longer you can shoot comfortably
 
Re: Light Vs Heavy rifle

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: seaaggie</div><div class="ubbcode-body">something you didn't hit on is how the rifle fits you. the better it fits, the less felt recoil you will have to deal with and the longer you can shoot comfortably </div></div>


Yes, actually I did. Not in my original post, no. But elsewhere in the thread I did. However that sounded just then, no disrespect meant by it.
 
Re: Light Vs Heavy rifle

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Cuga</div><div class="ubbcode-body">Mass of rifle multipied by the rifles velocity equals mass of bullet multiplied by muzzle velocity plus mass of powder multiplied by about 1.3 times muzzle velocity

the rifles velocity equals (mass of bullet multiplied by muzzle velocity plus mass of powder multiplied by about 1.3 times muzzle velocity) divided by mass of rifle

Rifles velocity squared multiplied by rifles mass divided by 2 equals recoil energy.

Sorry for this less than perfect writeup, but my cellphone sucks for this purpose.

ps: terminology </div></div>


AH HA!!!! Now we are getting somewhere. Now, if I can sit down and figure it out, instead of ASSUMING the above info is correct, instead of info meant to shoot over my head, LMAO!!

Just kidding of course.

Dont worry guys, none of this is meant to be taken too seriously. Just figured I would start up what I feel is an intersting debate, as I feel tht MOST people have just taken this info for granted, like I did, and assumed the theory was correct.

Im one of those that normally doesnt believe what is told to me, unless I see it for myself, or is PROVEN to me. Now, in a subject that I'm not an expert (and on guns, Im by no means, and expert), I will listen to the "expert", and chacnes are, believe it, UNLESS it sounds too far fetched. Then, I would want to see the proof in teh pudding, or a better explanation.

I also call people out if they are talking out of thier ass.
laugh.gif




EDIT: I can SPELL...just a real horrible typist. I make MANY typing errors, ESPECIALLY spelling "the". If you read enough of my posts, you will see that it normally (95% of the time) comes out "teh"
 
Re: Light Vs Heavy rifle

This is the problem with your analogy-yes, the object with more mass will impart more energy in a collision if both objects are moving at the same speed-but the objects are not moving at the same speed. Ignore the effect of the moving gasses for now (which actually contribute to the majority of felt recoil). If both bullets are leave the barrel at the same speed and weigh the same, then the heavier rifle moves in the opposite direction slower than the lighter rifle-that's momentum. How long are the barrels we're talking about here? There are a lot of factors that contribute to this, and simply saying that the masses and speeds are close enough to being the same is not enough, nor are the aggregate weights of the rifles enough to characterize them.
 
Re: Light Vs Heavy rifle

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: RedDevil</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Swampbuck</div><div class="ubbcode-body">Law of Physics.

Every action has an opposite and equal reaction.

If the bullet and rifle weighed the same they would both fly off in opposite directions. The weight of the rifle and absorbed recoil of the shooter is what keeps it(the rifle) from being a projectile itself.

a faster bullet (of the same weight) in a lighter rifle will kick faster (because the bullet is faster) and the shooter will absorb more recoil because the lighter rifle doesn't absorb as much recoil and more is passed to the shooter.

It is a physical law. If you feel that your heavier 308 kicks less than a 7mm mag it is because one of two things.

1. Stock fits you better and recoil pad is softer.
2. It's in your head and you have lost your objectivity. </div></div>

+1. If you shoot a 150 grain 308 out of both an 8lb rifle and a 10lb, the force of the projectile will propel the lighter rifle faster than the 10lb rifle. As for the VW bug and the 18 wheeler, they're both traveling at the same speed so yes, the 18 wheeler will cause more damage, BUT as I stated above, the projectile will not create the same force when shooting out of a heavier rifle as opposed to a light one. In essence, what I'm trying to say is that yes, <span style="font-style: italic"><span style="color: #FF0000">in theory you would be right that the heavier rifle would hit harder if it was thrown back with the same amount of force as a lighter one, which wouldn't happen if both are being shot with the same round. </span></span></div></div>


OK, now that is another sentence/piece of info that makes a lot of sense to me. Thanks. I can see what you are saying there.


So, that leads me to believe that SOMEWHERE there has to be a point of "diminishing returns".

IN other words, if said rifle (.308 in this case) produces "X" amount of energy, then said recoil will always be the amount, as long as you are shooting same weight bullet, right?
So, say it makes (just for simple math and english) 100Lbs of torque in felt recoil, with the determing FELT recoil all dependent upon the actual weight of the rifle. Everyone following me so far?
It's gonna push back say a 5 Lb rifle with 75 Lbs of torque, with that Torque being felt at point "A" on the buttpad of stock. OK?
So, with the same .308, but in a 10 Lb rifle, then at Point "A" we are gonna feel 70 Lbs of torque. Ok?

(this is under the assumption that I believe that in a lighter rifle you will feel more recoil, which Im still trying to determine if I do).


For some reason Im just thinking that there is a point to where the light rifle will hit less than a heavier rifle. Maybe it takes such a light rifle to do so, that we can't get that rifle light enough.

For example, say we could get a rifle (.308) down to say 1 Lb, (we could all agree that 1 Lb is not much weight), that with 100 Lbs of Torque pushing back 1 Lb, would not hit as hard as say a 10 Lb rifle being subjected to the same 100 Lb of torque.


I see that the projectile is leaving at a predetermined rate/velocity and is producing set amount of energy, but if there is "nothing" to hit you with that energy, then teh 'felt" recoil HAS to be less?

I guess it would almost be like placing a pillow between you and the rifle. Or a pencil being thrown at you.

DING DING DING DING..I THINK I GOT IT!!!!


OK, even though the rifle is very light (1Lb) when subjected to a certain amount of energy, it's gonna travel even faster (the object).

Say you take (I'm a car guy...build Hot Rods/Race Cars for a living) a Top Fuel Dragster setup, and watch it accellerate. Top Fuel Dragster produces @ 5 G's on take off. So, head and body is forced into the seat at an ungodly amount of force. Top Fuel Dragster (light rifle) then take teh SAME motor (the bullet) and place it in a 18 wheeler (Im on a big rig kick, leave me alone, LOL!). You will not be subjected to the same amount of G's on take off, even though the "bullet" is producing the same energy. Just takes more energy to get teh heavier vehicle moving, and in doing so, "FELT" recoil is less.

Hmmmmmmmmmmmm, Im thinking I get it..finally. Hahahahaha.

Yes, I can ramble on with teh best of 'em
 
Re: Light Vs Heavy rifle

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: rideHPD</div><div class="ubbcode-body">This is the problem with your analogy-yes, the object with more mass will impart more energy in a collision if both objects are moving at the same speed-but the objects are not moving at the same speed. Ignore the effect of the moving gasses for now (which actually contribute to the majority of felt recoil). If both bullets are leave the barrel at the same speed and weigh the same, then the heavier rifle moves in the opposite direction slower than the lighter rifle-that's momentum. How long are the barrels we're talking about here? There are a lot of factors that contribute to this, and simply saying that the masses and speeds are close enough to being the same is not enough, nor are the aggregate weights of the rifles enough to characterize them. </div></div>


They are both 26" barrels, my .308 being the Varmint Heavy barrel, and the 7MM (for time being) 26" pencil neck.

Im getting it, finally. Im just hard headed, and to make me see the "correct" answer on something I feel differently about, it normally takes an overwhelming amount of factual info to make me change my point of view.

The good? If enough facts are thrown my way, I can and will admit that I was wrong, or I see that the other way was correct.
Im at @ 95% to admitting I was wrong...not fully there, but getting damn close! HAHAHA!!!



I do have ONE last thing to maybe why I didnt FEEL as much recoil in my 7MM Rem Mag as I do on my .308.


tell me what you guys think about THIS:

As I said above, the 7MM Rem Mag rifle is an extremely light rifle, and the barrel is very very thin, so really thre is NO weight at the muzzle/towards end of rifle.

This rifle producs A LOT of muzzle jump, and I mean A LOT. My .308 pushes straight back into shoulder area with little to no muzzle jump. I can stay on target very weel with my .308. With teh 7MM, was impossible to stay on target with the amount of muzzle jump.


So, do you guys think that MAYBE said energy was "spent" lifting barrel/muzzle jump instead of pushing straight back into shoulder area, and in doing so, produced less felt recoil?
Look at it like this...say rifle produced so much muzzle jump, that the rifle actually did a "back flip"...chances are I wouldnt have "felt" any recoil, or very minimal, because all teh energy is being used to flip rifle over.

But on teh .308, with all teh "concentrated" energy going straight back into my shoulder, produced more "felt" recoil.


What about that theory? Hold water? Or, Im just nuts? LOL!!!It's good to be able to laugh at yoruself sometimes, or just laugh in general. Feels good.


OK....now that I got everyone's brains working overtime, riddle me this....
wink.gif
just kidding guys.

Thanks a ton for all teh info!
 
Re: Light Vs Heavy rifle

Why does this bring horrible flashbacks of physics classes? Cuga is right with his perspective of momentum, acceleration and kenetic energy.

Going back a few posts to the wood vs plastic bat comparison, direct comparison requires you give them the same 'momentum' ... this is represented by: p = mv

p (greek 'rho') = momentum
m = mass
v = velocity

If a wood bat is 30 oz and a plastic bat is 2 oz, and you're able to swing the plastic bat at 30 mph...

m1 * v1 = m2 * v2
30oz * v1 = 2oz * 30mph
30oz * v1 = 60 oz-mph
v1 = 2 mph

...would be like getting by a 30oz wood bat swinging at 2.67mph, or 1.36 fps. Not very scary.

Now to firearms ... why does everybody say a screaming 155 has lighter recoil than a 175?

155gr * 2900fps = 449,500
175gr * 2650fps = 463,750

This is also a REALLY simplified view with no friction, energy dissipation, etc as energy transfer is never direct & full. For instance, initiating a lighter object to even begin accelerating requires a lot less than a heavier object. There's a lot of lost work based on how planted the object is.

Part of what you mention re: muzzle flip seems correct -- per vector physics in the 7mm, energy is being transfered to angular acceleration which causing the straight-back onto you to feel a lot lighter. Think vectors like in windage ... a 10mph wind going sideways affects your bullet by the full 10mph, but going at a 45-degree angle affects your bullet only by about 7mph. For this one, think pythagorean's theorom ... a^2 + b^2 = c^2

Anyways, even if the rifles are in similar stocks, even the properties of the recoil pad will be a significant factor as a recoil pads ability to dampen & dissipate shock are all different. Limbsaver is so effective because of their patented NAVCOM which is (last time I researched them for home stereo app between speaker & stand) the world's most vibration dampening material.

Btw what bullet & estimated mv are you getting out of the 2 loads?
 
Re: Light Vs Heavy rifle

The shorter impulse of the lighter rifle might play a little into your perception of felt recoil, but really it's more likely a geometry problem in that the recoil isn't coming straight back, and there's a variance in the amount that is coming back into your shoulder, like you previously mentioned.
 
Re: Light Vs Heavy rifle

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Peepaw</div><div class="ubbcode-body">
Well, I think that teh 18 wheeler bug comparison is a rather good one myself, for the reasons below:

<span style="color: #CC0000"><span style="font-weight: bold">1)Both traveling same speed (bullet velocity/weight)</span></span>
2)Wall they hit is "you" the shooter.
3)weight of each vehicle is the weight of each rifle. Heavier vehicle is carrying more mass, and in doing so, carries more energy., and in doing so, hits harder. </div></div>

This is where your analogy is wrong. They (the rifles) are NOT both moving at the same speed. The 7mm Mag is moving to the rear much faster, and with correspondingly greater recoil energy than is your .308 Win. Did you look at the "recoil chart" I posted earlier? Again, if you "feel" less recoil with the 7 Mag, it is because of some other mitigating factor.
 
Re: Light Vs Heavy rifle

How long are the barrels of each?

Also, I've had sorta the same kinda thoughts about AR-15's vs. AK-47's.

An AR 'seems' to me to have more of a 'bite' to the recoil while an AK has more of a 'push'

I chalked it up to how the rifles work, and AR has a straight line recoil pattern into the buttstock, while an AK is off center.

However, I believe that the incredibly large and heavy bolt carrier on the AK absorbs and decelerates the recoil action better than the AR. Why? The AR has a smaller bolt carrier and recoils inline with the buttstock.

However, with good shooting posture, slings and training both can be used equally effectively.

This leads me to think, are your scope rings the same height? You may be getting a different line of recoil into your body by how you hold the stock.

Honestly, when I shoot now days, I barely ever notice recoil unless it is obtrusive. I too shoot a 7mm Rem Mag and don't notice it, but I also don't notice my 30-06, 303, or mosin. However I do notice the muzzle rise on my AK when shooting several rounds in quick succession, I have to work at keeping my sight picture correct and on target (plus trigger release, etc.)
 
Re: Light Vs Heavy rifle

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Peepaw</div><div class="ubbcode-body">
They are both 26" barrels, my .308 being the Varmint Heavy barrel, and the 7MM (for time being) 26" pencil neck.
</div></div>
 
Re: Light Vs Heavy rifle

Yrs ago I had the oppritunity to pick up a Rem 700 264Win Mag in an aftermarket Fajun stock. 264's are not known to be a "kicker". Well that one was the stompinist sob I have ever shot in my life. It was quick, sharp, and came up in a hurry too! Needless to say it went down the road very quick. It had to be style of the stock. Stock designs are very important to how rifles recoil. I dare say in 2 identical rifles the 7mm will recoil more than the 308.
 
Re: Light Vs Heavy rifle

Few rifle shooters shoot as much as AA handicap trap shooters and few are as finicky about fit. Ask any of them if there is any difference in recoil between a 6.5# gun and a 9# gun.
 
Re: Light Vs Heavy rifle

30-06 springfield - 168 gr accubond.
300WSM Montana - 168 Accubond.

They recoil different. The duration of the Springfield recoil is longer, The Montana is short and harsh.

SPringfield is over 12 lbs.
Montana is < 7.

The Springfield also has a curley maple stock, the Montana a rigid Kevlar with aluminum bedding.

I think in my case weight is one factor, and the stocks ability to absorb energy is the other. The wood stock flexes where the wonder plastic and aluminum is rigid so my shoulder has to flex to absorb the recoil.
smile.gif


Besides the mass,energy you have rate of acceleration(Speed of the powder) and duration of acceleration (How much powder and how long it burns).

Dave
 
Re: Light Vs Heavy rifle

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Hamstur</div><div class="ubbcode-body">Why does this bring horrible flashbacks of physics classes? Cuga is right with his perspective of momentum, acceleration and kenetic energy.

Going back a few posts to the wood vs plastic bat comparison, direct comparison requires you give them the same 'momentum' ... this is represented by: p = mv

p (greek 'rho') = momentum
m = mass
v = velocity

If a wood bat is 30 oz and a plastic bat is 2 oz, and you're able to swing the plastic bat at 30 mph...

m1 * v1 = m2 * v2
30oz * v1 = 2oz * 30mph
30oz * v1 = 60 oz-mph
v1 = 2 mph

...would be like getting by a 30oz wood bat swinging at 2.67mph, or 1.36 fps. Not very scary.

Now to firearms ... why does everybody say a screaming 155 has lighter recoil than a 175?

155gr * 2900fps = 449,500
175gr * 2650fps = 463,750

This is also a REALLY simplified view with no friction, energy dissipation, etc as energy transfer is never direct & full. For instance, initiating a lighter object to even begin accelerating requires a lot less than a heavier object. There's a lot of lost work based on how planted the object is.

Part of what you mention re: muzzle flip seems correct -- per vector physics in the 7mm, energy is being transfered to angular acceleration which causing the straight-back onto you to feel a lot lighter. Think vectors like in windage ... a 10mph wind going sideways affects your bullet by the full 10mph, but going at a 45-degree angle affects your bullet only by about 7mph. For this one, think pythagorean's theorom ... a^2 + b^2 = c^2

Anyways, even if the rifles are in similar stocks, even the properties of the recoil pad will be a significant factor as a recoil pads ability to dampen & dissipate shock are all different. Limbsaver is so effective because of their patented NAVCOM which is (last time I researched them for home stereo app between speaker & stand) the world's most vibration dampening material.

Btw what bullet & estimated mv are you getting out of the 2 loads? </div></div>



OH SNAP!!!! Now see...I KNEW we had a brainiac out there somewhere, just WAITING to hook me up. I knew thre had to be a physics answer/solution to my question/equation.
YES! Now, I am offically 100% sold.

THANKS!!!!!!


(even though most of it was over my head, it sure sounded impressive as hell!)
 
Re: Light Vs Heavy rifle

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Scoop</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Peepaw</div><div class="ubbcode-body">
Well, I think that teh 18 wheeler bug comparison is a rather good one myself, for the reasons below:

<span style="color: #CC0000"><span style="font-weight: bold">1)Both traveling same speed (bullet velocity/weight)</span></span>
2)Wall they hit is "you" the shooter.
3)weight of each vehicle is the weight of each rifle. Heavier vehicle is carrying more mass, and in doing so, carries more energy., and in doing so, hits harder. </div></div>

This is where your analogy is wrong. They (the rifles) are NOT both moving at the same speed. The 7mm Mag is moving to the rear much faster, and with correspondingly greater recoil energy than is your .308 Win. Did you look at the "recoil chart" I posted earlier? Again, if you "feel" less recoil with the 7 Mag, it is because of some other mitigating factor. </div></div>


Hey scoop...well, I guess you didnt read any of my posts in the middle...or you missed it to where I changed up teh caliber. I said let's use teh SAME caliber (I just took teh .308 as an example) and use it in different weight rifles.

yes, I did look at teh chart, thanks. I havent "studied" it yet, but did notice that 168 in .308 was @ 160 and 7MM 160 grain was @ 275...Ill check it out more in depth later on.
 
Re: Light Vs Heavy rifle

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Peepaw</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Scoop</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Peepaw</div><div class="ubbcode-body">
Well, I think that teh 18 wheeler bug comparison is a rather good one myself, for the reasons below:

<span style="color: #CC0000"><span style="font-weight: bold">1)Both traveling same speed (bullet velocity/weight)</span></span>
2)Wall they hit is "you" the shooter.
3)weight of each vehicle is the weight of each rifle. Heavier vehicle is carrying more mass, and in doing so, carries more energy., and in doing so, hits harder. </div></div>

This is where your analogy is wrong. They (the rifles) are NOT both moving at the same speed. The 7mm Mag is moving to the rear much faster, and with correspondingly greater recoil energy than is your .308 Win. Did you look at the "recoil chart" I posted earlier? Again, if you "feel" less recoil with the 7 Mag, it is because of some other mitigating factor. </div></div>


Hey scoop...well, I guess you didnt read any of my posts in the middle...or you missed it to where I changed up teh caliber. I said let's use teh SAME caliber (I just took teh .308 as an example) and use it in different weight rifles.

yes, I did look at teh chart, thanks. I havent "studied" it yet, but did notice that 168 in .308 was @ 160 and 7MM 160 grain was @ 275...Ill check it out more in depth later on. </div></div>

It's all good Peepaw. You finally arrived at the right answer
grin.gif
All other factors (stock fit, recoil pad, muzzle brakes, etc) being equal, the lighter rifle will always "kick" harder than the heavier one in the same caliber and certainly so when the lighter rifle is in a more powerful caliber.
 
Re: Light Vs Heavy rifle

The slower burning powder in a 7mm Mag will push more but the faster burning powder of a .308 will hit more...
 
Re: Light Vs Heavy rifle

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Scoop</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Peepaw</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Scoop</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Peepaw</div><div class="ubbcode-body">
Well, I think that teh 18 wheeler bug comparison is a rather good one myself, for the reasons below:

<span style="color: #CC0000"><span style="font-weight: bold">1)Both traveling same speed (bullet velocity/weight)</span></span>
2)Wall they hit is "you" the shooter.
3)weight of each vehicle is the weight of each rifle. Heavier vehicle is carrying more mass, and in doing so, carries more energy., and in doing so, hits harder. </div></div>

This is where your analogy is wrong. They (the rifles) are NOT both moving at the same speed. The 7mm Mag is moving to the rear much faster, and with correspondingly greater recoil energy than is your .308 Win. Did you look at the "recoil chart" I posted earlier? Again, if you "feel" less recoil with the 7 Mag, it is because of some other mitigating factor. </div></div>


Hey scoop...well, I guess you didnt read any of my posts in the middle...or you missed it to where I changed up teh caliber. I said let's use teh SAME caliber (I just took teh .308 as an example) and use it in different weight rifles.

yes, I did look at teh chart, thanks. I havent "studied" it yet, but did notice that 168 in .308 was @ 160 and 7MM 160 grain was @ 275...Ill check it out more in depth later on. </div></div>

It's all good Peepaw. You finally arrived at the right answer
grin.gif
All other factors (stock fit, recoil pad, muzzle brakes, etc) being equal, the lighter rifle will always "kick" harder than the heavier one in the same caliber and certainly so when the lighter rifle is in a more powerful caliber. </div></div>

Yes sir, it sure is my friend! It's ALL good!

yeah sometimes I just get hung up on something, and will toss it around, and then it becomes an obsession. So, you REALLY try and sell yourself on it,disregarding other's advice. So, it normally (as I said above) takes a pretty good, factual based answer to get me to change my mind, or at least admit I MIGHT be wrong.

Plus, I just like discussing stuff like that anyways. My wife says I should've been an attorney because I'm real hard headed, and I can do a heck of a job selling someone on something (like a not guilty verdict). I may not have been able to get my point as strongly across as I would have liked to, here on the internet, but let me get you in person, face to face, and man, I bet you I can get the best of them thinking I'm right! HAHAHA!!!
 
Re: Light Vs Heavy rifle

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: CrawDad338</div><div class="ubbcode-body">The slower burning powder in a 7mm Mag will push more but the faster burning powder of a .308 will hit more... </div></div> Huh, how much longer does it take a bullet to exit the bbl in a 7mm Mag than a 308? Of course same bbl length and bullet weight to make things simple. It all happens so quick I think this is irrelevent. krw
 
Re: Light Vs Heavy rifle

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: krw</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: CrawDad338</div><div class="ubbcode-body">The slower burning powder in a 7mm Mag will push more but the faster burning powder of a .308 will hit more... </div></div> Huh, how much longer does it take a bullet to exit the bbl in a 7mm Mag than a 308? Of course same bbl length and bullet weight to make things simple. It all happens so quick I think this is irrelevent. krw </div></div>
A difference in barrel lengths would distinguish the effect of this more, but a faster burning powder would coincide with a faster acceleration of the rifle. Because of the faster acceleration, the force felt on the shoulder is greater while the rifle is compressing the shoulder tissue. The sensation of being "hit" and bruising is caused by shearing of the muscle, which occurs during the displacement of the rifle during the recoil impulse. To put it in lamer terms, if the rifle moves into the shoulder pocket faster, it will cause more tissue damage and be felt more by the shooter than a slower impulse will, where a majority of the recoil impulse is felt while the rifle is fully pushed into the stock. This is why you would feel more discomfort/bruise easier if you have more fat than muscle where the stock contacts the body because fat is more compressible and has a lower modulus, meaning that it can be displaced more with less force.
 
Re: Light Vs Heavy rifle

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: krw</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: CrawDad338</div><div class="ubbcode-body">The slower burning powder in a 7mm Mag will push more but the faster burning powder of a .308 will hit more... </div></div> Huh, how much longer does it take a bullet to exit the bbl in a 7mm Mag than a 308? Of course same bbl length and bullet weight to make things simple. It all happens so quick I think this is irrelevent. krw </div></div>

There are slower burning powders and faster burning powders, it's really that simple. For contrast when I shoot my .338 Lapua on the side of my .308, the .308 dings my shoulder a little more where my .338 is a more gradual extended push. General rule of thumb is a bigger case needs slower burning powder..

This may not be the best analogy, but I think of 308 powder burn as snappy and the big boomers as torquey...

Your logic is like saying all powders are so close others are "irrelevant" why not use one for all calibers...
 
Re: Light Vs Heavy rifle

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: rideHPD</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: krw</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: CrawDad338</div><div class="ubbcode-body">The slower burning powder in a 7mm Mag will push more but the faster burning powder of a .308 will hit more... </div></div> Huh, how much longer does it take a bullet to exit the bbl in a 7mm Mag than a 308? Of course same bbl length and bullet weight to make things simple. It all happens so quick I think this is irrelevent. krw </div></div>
A difference in barrel lengths would distinguish the effect of this more, but a faster burning powder would coincide with a faster acceleration of the rifle. Because of the faster acceleration, the force felt on the shoulder is greater while the rifle is compressing the shoulder tissue. The sensation of being "hit" and bruising is caused by shearing of the muscle, which occurs during the displacement of the rifle during the recoil impulse. To put it in lamer terms, if the rifle moves into the shoulder pocket faster, it will cause more tissue damage and be felt more by the shooter than a slower impulse will, where a majority of the recoil impulse is felt while the rifle is fully pushed into the stock. This is why you would feel more discomfort/bruise easier if you have more fat than muscle where the stock contacts the body because fat is more compressible and has a lower modulus, meaning that it can be displaced more with less force. </div></div>
Then how about the muzzle velocity difference between the two? The 7mm is going to be a lot faster than the 308 pushing the same weight bullet. Not to mention the difference in charge weight, and the larger amount of burning gases from the 7mm round.
Your argument for slower/faster powder only works for rifles of the caliber, but even then the difference in velocity would be the end of it...
 
Re: Light Vs Heavy rifle

Recoil is based on muzzle energy and the amount of time it takes for powder to burn compared to the weight of the gun. Time vs energy vs weight. Let's use the same gun, same bullet weight, and two different powders loaded where the muzzle velocity is exactly the same with both, the total applied recoil would be exactly the same for both loads. When you figure burn rate or time into the equation, "felt recoil" will be sharper with the faster burning powder.
 
Re: Light Vs Heavy rifle

What crawdad said; I was only explaining how powder burn rate affects recoil, with everything else held constant. Whether or not that is the deciding factor is something I'm not going to comment on bc there are too many variables to really get solid information without doing the tests yourself.
 
Re: Light Vs Heavy rifle

Hey guys, REMEMBER, after my original post, I said, for simplicity, let's keep caliber teh SAME.


That way we can just argue over light vs heavy, and not have a debate over which caliber hits harder, then ading in different weight rifle's, I think added to more argument than was necessary.


I only mentioned that, because after being told to expect to be hit harder with the 7MM, and especially because of it being a lighter rifle than my .308, I was just caught by surprise when my SHOULDER was telling me I was being hit harde by my .308.


So, now that we are comparing the EXACT SAME CALIBER, the debate (which, in my eye's, because of some terminology above, has now sold me on heavy vs light debate) is now simply over light vs heavy rifle.

Now, feel free to add to the discussion, but the OP (that would be me of course) is now officially satisified in this debate.


Thanks to all that have added (more some than other's of course), your opinion, as I have enjoyed ALL of the post's.
 
Re: Light Vs Heavy rifle

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: rideHPD</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: krw</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: CrawDad338</div><div class="ubbcode-body">The slower burning powder in a 7mm Mag will push more but the faster burning powder of a .308 will hit more... </div></div> Huh, how much longer does it take a bullet to exit the bbl in a 7mm Mag than a 308? Of course same bbl length and bullet weight to make things simple. It all happens so quick I think this is irrelevent. krw </div></div>
A difference in barrel lengths would distinguish the effect of this more, but a faster burning powder would coincide with a faster acceleration of the rifle. Because of the faster acceleration, the force felt on the shoulder is greater while the rifle is compressing the shoulder tissue. The sensation of being "hit" and bruising is caused by shearing of the muscle, which occurs during the displacement of the rifle during the recoil impulse. To put it in lamer terms, if the rifle moves into the shoulder pocket faster, it will cause more tissue damage and be felt more by the shooter than a slower impulse will, where a majority of the recoil impulse is felt while the rifle is fully pushed into the stock. This is why you would feel more discomfort/bruise easier if you have more fat than muscle where the stock contacts the body because fat is more compressible and has a lower modulus, meaning that it can be displaced more with less force. </div></div>



This is another one of my favorites.
cool.gif
For all I know, it's all BS, but man, it sure does sound like he knows what he is saying, LMAO!!!


Just kidding of course, as I know what you are saying..it's just Wed night, and feeling, well, pretty damn good.
 
Re: Light Vs Heavy rifle

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: JWP6114</div><div class="ubbcode-body">I just make'em go bang...
grin.gif
</div></div>

+1

I also think it's a little ironic that your signature quote says what it does. Not really coinciding with your respose to this discussion.
 
Re: Light Vs Heavy rifle

243 Light or Med palma barrel fluted 90% Carbon Stock
30-06 M24 DEEP AS I CAN fluted Standered Fill stock
338 Deep fluted M24 Standered fill
223 AI LIGHT palma 90% carbon Stock
284 M24 (ONLY because I got it in a trade Standered fill

I love em like my women, thick and thin.