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How short on a 308 barrel? Range Report in

LongArm

LongArm

Problem Solver
Full Member
Minuteman
Apr 30, 2007
1,206
21
Corpus Christi, Texas
I want to cut my 308 barrel down shorter. I will be making shot no longer than 600 yards. I would like to cut it to 16-17". Useing Federal gold match as an example, would 16" be to short? Would 16" have excessive amount of drop compared to say a 20" barrel at 500 yards?

<span style="text-decoration: underline"><span style="font-weight: bold">Range report on page 2</span></span>
 
Re: How short on a 308 barrel?

16" for 600 yards is fine. Handy too:)
It will have more drop but I wouldn't call it excessive.
 
Re: How short on a 308 barrel?

Its all about velocity... 18-20" has been pretty well established to work to 1k with factory 175 loads. 16" will absolutely stay supersonic to 600... But how good are you at reading wind? Because that is where the velocity difference will be noticed most.
 
Re: How short on a 308 barrel?

I guess I will take the other side of the argument.

What will you gain from cutting it down?

I have never had a problem with my 26" 700 at a range or at competitions. I really haven't even seen much problem with it when patrolling through the woods (with some pretty thick growth).

Where I have problems with it is out in the real world moving through stairwells, houses and packing it in the trunk of cars.

I now use a 20" for work because it packs smaller, and is easier to move with when I am in a confined space.

If it's a working rifle, cut it down.
If it's a brush gun, cut it down.
If you are going to suppress it, cut it down.

If you shoot on the range, and the rifle is shooting well now, leave it alone.

Cutting it for the sake of cutting it will just increase muzzle blast, decrease efficiency with factory ammo and slightly increase perceived recoil from the reduction of weight at the muzzle.
 
Re: How short on a 308 barrel?

How short you go will only effect MV, and thus, max range and the amount of dope (windage and elevation) required to get you on target at those ranges. Accuracy from a quality barrel should not vary regardless of the length. The bullet/load you chose will have more to do with performance at extended ranges. If you reload, you can overcome a good bit of lost MV from going from say a 20" to a 16" tube just by pushing your reloads a little faster. I have swicthed to running 155gr Scenars out of my short-barreled .308 rifles because you get a high BC for better performance/stability at extended ranges and you also get excellent MV compared to bullets like the 175gr SMKs and similar bullets.

If you don't reload, then your MV loss is what it is. Not all barrels were created equally, but as an estimate...you will lose somewhere between 100-200fps going from a 20" to a 16" barrel.

Taking a 175gr SMK for example, here are a "guesstimates" on drop for you:

175gr SMK from a 20" barrel gets around 2600fps, so your approx. adjustments to 600 (again...purley guesses...in MOA) will be:

100 - 0.0 (assuming a 100yd zero)
200 - 2.1
300 - 5.0
400 - 8.3
500 - 12.1
600 - 16.4

The same 175gr SMK from a 16" barrel gets around 2450fps, which equates to:

100 - 0.0 (assuming a 100yd zero)
200 - 2.5
300 - 5.8
400 - 9.6
500 - 13.9
600 - 18.8

Anyway...as I said...these are estimates only for the sake of showing you an approximation of where you'll be comparing a 20" to a 16" tube in terms of MV and the adjustments needed at your stated max range of 600yds. You are looking at roughly a 2MOA difference (not a lot) at 500yds and 600yds between the two barrel lengths.
 
Re: How short on a 308 barrel?

Not to hijack, but food for thought. I'll pose this question and think it is relative to the OP question. If not I will post it in my own thread.

Would a .299" (tight bore) bring up the lost velocities when cutting down barrel length??? Let's say from 20" to 16". Therefore a .299 tightbore 16" may be equal to a .300 bore 20"??? I have no experience with the tightbore .308s but I too an looking to build a shorty (18-20") in he near future. I am thinking of going the .299 tightbore route to get the velocities up. Any issues or drawbacks with this idea?
 
Re: How short on a 308 barrel?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Tangodown911</div><div class="ubbcode-body">
Would a .299" (tight bore) bring up the lost velocities when cutting down barrel length??? Let's say from 20" to 16". Therefore a .299 tightbore 16" may be equal to a .300 bore 20"??? I have no experience with the tightbore .308s but I too an looking to build a shorty (18-20") in he near future. I am thinking of going the .299 tightbore route to get the velocities up. Any issues or drawbacks with this idea?

</div></div>

I think I would accept the loss of MV before I would risk reliability or similar risks from a tighter bore...

In fact thats exactly what I'm doing with my 18.5" barrel 308 in build right now.
 
Re: How short on a 308 barrel?

I run the same loads through a .300"/.3080" bore as I do a .298"/.3065" with no ill effects. Both rifle chambers cut with the same reamer.

Can't compare the velocities though as the standard dia barrel is 23.5" and the tight bore/groove one is 30".

I even run NATO ammo thru the 23.5" and lived to tell about it. Guess I just like to live dangerously, ignoring two Internet myths in one chambering across two rifles.
 
Re: How short on a 308 barrel?

The reason I am looking to cut the barrel down is because it would be a lot easier to get in and out of places deer blind,truck, walking through south Texas brush to look for hogs, and the farthest I have ever shot it is 550 yards. I do reload for it and could tailor the loading for the length.
 
Re: How short on a 308 barrel?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: ORD</div><div class="ubbcode-body">How short you go will only effect MV, and thus, max range and the amount of dope (windage and elevation) required to get you on target at those ranges. Accuracy from a quality barrel should not vary regardless of the length. The bullet/load you chose will have more to do with performance at extended ranges. If you reload, you can overcome a good bit of lost MV from going from say a 20" to a 16" tube just by pushing your reloads a little faster. I have swicthed to running 155gr Scenars out of my short-barreled .308 rifles because you get a high BC for better performance/stability at extended ranges and you also get excellent MV compared to bullets like the 175gr SMKs and similar bullets.

If you don't reload, then your MV loss is what it is. Not all barrels were created equally, but as an estimate...you will lose somewhere between 100-200fps going from a 20" to a 16" barrel.

Taking a 175gr SMK for example, here are a "guesstimates" on drop for you:

175gr SMK from a 20" barrel gets around 2600fps, so your approx. adjustments to 600 (again...purley guesses...in MOA) will be:

100 - 0.0 (assuming a 100yd zero)
200 - 2.1
300 - 5.0
400 - 8.3
500 - 12.1
600 - 16.4

The same 175gr SMK from a 16" barrel gets around 2450fps, which equates to:

100 - 0.0 (assuming a 100yd zero)
200 - 2.5
300 - 5.8
400 - 9.6
500 - 13.9
600 - 18.8

Anyway...as I said...these are estimates only for the sake of showing you an approximation of where you'll be comparing a 20" to a 16" tube in terms of MV and the adjustments needed at your stated max range of 600yds. You are looking at roughly a 2MOA difference (not a lot) at 500yds and 600yds between the two barrel lengths. </div></div>

Thanks for the info! Where did you get this "estimate" from? By this estimate it sounds like there is not much difference in the two lengths. I am sure that the slower bullets will be effected more by the wind.
 
Re: How short on a 308 barrel?

I may have asked this on another thread but don't remember the answer... Does twist rate come into play when discussing shortening a barrel?
 
Re: How short on a 308 barrel?

I guess that makes since to run a lighter bullet to get it going faster in a short barrel. I have no experience with the 155 scenars, I wonder if the 168A-Max would be an acceptable trade off?
 
Re: How short on a 308 barrel?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: LongArm</div><div class="ubbcode-body">Thanks for the info! Where did you get this "estimate" from? By this estimate it sounds like there is not much difference in the two lengths. I am sure that the slower bullets will be effected more by the wind.
</div></div>

The 2600 is my experience (generally) with factory 20" tubes, using FGMM 175gr factory ammo. Take an average of between 100fps and 200fps loss in MV (150fps) and subtract that from the 2600fps to get a guessed 16" barrel MV of 2450fps. Program that into whatever your poison might be for a ballistics program and poof...out come the numbers. As for faster versus slower bullets bucking the wind better...well, a whole host of factors play into that including bullet type and weight, but generally faster is better.

As for barrel twist...your 1:10 is perfect for use on a shorter barrel with heavier bullets.

As for the 168gr A-Max...it will fare better than the 168gr SMK's in terms of having a higher BC, but it still isn't a good as the 155gr Scenars from my experience. However, since you are only shooting out to 600yds, any quality match bullet will work great from 155gr to 178gr. If you want a hunting bullet, then try out the Barnes T-TSX and MRX bullets.
 
Re: How short on a 308 barrel?

The reason for the short barrels is to cut some weight so that the rifle is still conveniently portable when a suppressor is mounted. An 18" 308 with a suppressor is similar to a 24" rifle without one.

308 loses velocity slowly down to 18 1/2", but after that, velocity falls off faster, and the losses are more significant. The short barrels can still work if higher BC bullets are used at long range.

A longer barrel is your friend at longer ranges, but sometimes it's more about how the rifle handles. For a Rem action, the 20" LTR with the fluted bbl has proven to be a good handling package for varied uses, and can perform adequately at the range and in the field with the right loads.

TC
 
Re: How short on a 308 barrel?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Top Cat</div><div class="ubbcode-body">The reason for the short barrels is to cut some weight so that the rifle is still conveniently portable when a suppressor is mounted. An 18" 308 with a suppressor is similar to a 24" rifle without one.

308 loses velocity slowly down to 18 1/2", but after that, velocity falls off faster, and the losses are more significant. The short barrels can still work if higher BC bullets are used at long range.

A longer barrel is your friend at longer ranges, but sometimes it's more about how the rifle handles. For a Rem action, the 20" LTR with the fluted bbl has proven to be a good handling package for varied uses, and can perform adequately at the range and in the field with the right loads.

TC </div></div>

ok just to clarify are we talking about 18.5" of rifling or 18.5" of total barrel?
 
Re: How short on a 308 barrel?

I run an 18" barrel on my comp gun and absolutely love it. It is way handier than most bolt rifles I've shot in my lifetime. The only problem is that now I've got a helluva time convincing myself to go with a 24-26" tube for my upcoming ELR rig.
 
Re: How short on a 308 barrel?

Barrel length is always stated as total barrel length, not just what the bullet sees, so that's 18.5" as measured from the bolt face to the end of the barrel.

TC
 
Re: How short on a 308 barrel?

A lot of a rifle's "handiness" is in how the rifle balances. Remys feel muzzle heavy to me, so I prefer them to be shorter, but I have 24" heavier barreled rifles that balance so well they handle like sporters.

TC
 
Re: How short on a 308 barrel?

LongArm...I'm running a 700 with a 16.5 inch barrel, 1:10 twist, using reloads with 175 SMK's and 175 FGGM. For the distance that you are talking about the length will be fine. The velocity I am getting is right at 2460 with the factory loads, I tailor my reloads to match my duty rounds. You will have no issues reaching 550 plus with out any issues. To give you an example, I was running mine out to 700 yds today with 24 MOA dailed in with some really good results. Hope this helps.

B.
 
Re: How short on a 308 barrel?

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">..........
I have never had a problem with my 26" 700 at a range or at competitions. I really haven't even seen much problem with it when patrolling through the woods (with some pretty thick growth).

Where I have problems with it is out in the real world moving through stairwells, houses and packing it in the trunk of cars.

I now use a 20" for work because it packs smaller, and is easier to move with when I am in a confined space.

If it's a working rifle, cut it down.
If it's a brush gun, cut it down.
If you are going to suppress it, cut it down.

If you shoot on the range, and the rifle is shooting well now, leave it alone........ </div></div>
My mantra is: if it's a working rifle - use a bullpup; if it's a brush gun - use a bullpup; if it's going to wear a can - use a bullpup. Saves you about 10"-12" of barrel length right there (or more - depending).
wink.gif


<span style="font-style: italic">You wouldn't believe how easily a bullpup - even in a Pelican case - slides into a small-sized (smaller than Honda!) sedan trunk!
wink.gif
</span>
 
Re: How short on a 308 barrel?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Winny</div><div class="ubbcode-body">LongArm...I'm running a 700 with a 16.5 inch barrel, 1:10 twist, using reloads with 175 SMK's and 175 FGGM. For the distance that you are talking about the length will be fine. The velocity I am getting is right at 2460 with the factory loads, I tailor my reloads to match my duty rounds. You will have no issues reaching 550 plus with out any issues. To give you an example, I was running mine out to 700 yds today with 24 MOA dailed in with some really good results. Hope this helps.

B. </div></div>

Yes it does thx. I am leaning towards 17-18" but 16" would be tits!
 
Re: How short on a 308 barrel?

I have a Bartlein tight bore 308 barrel that I am getting ready to send off to Randy for my built and he is going to cut it down to 16.25" for me, threaded for a can. I'll do a full write up once I get it back.
 
Re: How short on a 308 barrel?

308 works better than most with short barrels,I had a 308 LR308 18" with 190's at 2450fps from a bolt gun 18" I shot 208 amax at 2550 using RL17 on the bolt and RL15 on the LR308 I used the brass 5 times easy,Now add a CAN and some summer heat and I LOST SOME BRASS..

Shorter is less efficient with powder and burn so it will bark harder because you run max load to get what you lose back,Or let BC rule and drive it slower..
 
Re: How short on a 308 barrel?

I'm looking forward to testing out some of the new Hornady Superformance 178 BTHP ammo. It is suppose to be about 100fps hotter than FGGM and BHs. This ammo plus the tight bore might be the perfect combo of factory ammo.
 
Re: How short on a 308 barrel?

I dont really get the whole short barrel fad...

I hear lot of talk about short vs. long barrel accuracy. I believe they can both be accurate. What is important to me is hitting my target at a given distance. The further away the target the more wind comes into play.

I ran some numbers in QuickLoad to compare wind drift vs. barrel length. I used a .308, new SMK 155s and the powder which gave the greatest velocity at a set PSI per barrel length. I believe it is important to choose the best powder maximizing velocity at each length.

<div class="ubbcode-block"><div class="ubbcode-header">Code:</div><div class="ubbcode-body ubbcode-pre" ><pre>Barrel fps Drift 500 Drift 1000
32 3060 18 90.4
28 2988 18.7 94.2
24 2902 19.6 99.1
20 2793 20.8 106
16 2648 22.5 116.1</pre></div></div>

As you can see the 32" barrel will shoot "inside" the 16" barrel by 4.5" @ 500 & 25.7" @ 1000. I know that is an extreme example but barrel length adds velocity and velocity is our friend. A short barrel might be worth it to you for weight or size but it does come at a cost.

Note a tight bore only help with factory ammo... us reloading types just add powder.
 
Re: How short on a 308 barrel?

That makes a lot of since. The reasoning behind the short barrel for me is mobility, weight and relative known distance shooting (ie... less than 600yards).
 
Re: How short on a 308 barrel?

My build in another thread, has a 28" McGowen SS match barrel in 1 in 10 twist (.308) I went longer to gain the extra MV. What bullet would you expect to fly best to 1000 yards.

If I am off base asking here, I will post a new thread (Noobie)
 
Re: How short on a 308 barrel?

There is no denying that a shorter barrel is the way to go in an urban setting or when using a can.

Is this why you want the shorter barrel?
 
Re: How short on a 308 barrel?

GAP 18" and its a shooter out to 1k. I have not seen any major drop. Short is the way to go in my opinion.
 
Re: How short on a 308 barrel?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: TDECK</div><div class="ubbcode-body"> There is no denying that a shorter barrel is the way to go in an urban setting or when using a can.

Is this why you want the shorter barrel? </div></div>

i wish, eventually i will get one just not now
 
Re: How short on a 308 barrel?

17.5 length is good. As I stated before, it will get you to the distance you need. I shoot on a weekly basis with several other guys running factory and custom .308's with 20, 24, and 26 inch barrels and I see little differnce in our wind calls out to 700 yards or so..after that, I need to pay a bit more attention. By going with a short barrel, you get what you get, a good, accurate, portable, light, platform that will perform fine out to 700 yards or so without any issue. Good Luck!
 
Re: How short on a 308 barrel?

I cut mine down from a 24" to a 20" (11 degree recrown), this is a cheap Adams & Bennett 1:10 twist, my shots went from a 4" group to a 1" group @ 100 yards, I think she would do better if a better trained person would shot it.....

Again the only reason I shortened the barrel was because it was a cheap barrel and wanted to see if it would improve the accuracy. I do not recommend it if you have a Shilen or Krieger or any other great barrel. I would just by another rifle in the length you want.....
 
Re: How short on a 308 barrel?

I do believe I will be chopping my AW barrel from 26" to 16-18". I have a can coming any day now (I hope, pending my form 4 approval!!!) and I want the shorter OAL. Without a can, I prefer a longer barrel because the blast is significant enough to produce a flinch on a shorter barrel.
 
Re: How short on a 308 barrel?

WOW! That sure looks shorter than 17.5" to me, but it looks really good!

Looking forward to a range report. Be sure to run your chrono to get a baseline of where you are at now in terms of MV with the shorter bbl and the ammo you'll be using.
 
Re: How short on a 308 barrel?

LongArm, no arguing on how handy that rifle is. Looks great as well!
 
Re: How short on a 308 barrel?

I must just be that old school (and I'm 28) that a longer barrel can't hurt so I never chop my barrels.

Unless someone can enlighten me as to what harm 4" or 6" extra barrel could possibly do...

I could see a Police Marksman needing to shorten their barrel for obvious tactical and practical reasons... but for the rest of us???
 
Re: How short on a 308 barrel?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: JelloStorm</div><div class="ubbcode-body">I must just be that old school (and I'm 28) that a longer barrel can't hurt so I never chop my barrels.

Unless someone can enlighten me as to what harm 4" or 6" extra barrel could possibly do...

I could see a Police Marksman needing to shorten their barrel for obvious tactical and practical reasons... but for the rest of us??? </div></div>

I did it for this...
gun003.jpg
 
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