.308 tumbling at (almost) a mile.

[BillyGoatMachine]

Long range noob here with some questions. Basically I was under the impression that a .308 would be tumbling by the time it reached it's target when shooting out to a mile. Now the reason I believed this is because just last week I was shooting my .338 out to 1585 and having fantastic results. I decided to try out my Warner build .260 just to see if I could get some hits at this distance. I eventually did have about 3-5 hits on a 24x24" steel out of about 20 rounds. Upon inspection of the target there were clearly visible strikes that showed the bullet impacting sideways. Essentially keyhole imprints on the target. So I was bragging to a friend about getting hits at almost a mile and he decided a few days later to head out with his .308 Thunder Ranch. I was not there but he did send me a picture barraging about how his TR was having consistent hits at 1680. And he wasn't experiencing any bullet tumbling. So by my limited knowledge I was under the impression that a .260 would have much better chances than a .308 at these distances. What gives?







His target,


My target last week. In the lower left you can clearly see 2 bullet strikes that appeared to have hit sideways. I even found a complete 260 pill with a dent in the side of it as it appeared to have struck the top of the steel as it tumbled to the target. I think a few shots might have hit straight on along with the sideways hits.




My rifle,

Warner Tool built .260
Bartlein 23" tube
Huber trigger
139g Scenars @2775 fps
S&B 5-25

His rifle,

Gap Thunder Ranch
22" barrel
175g Sierra MK @2750 fps (ballpark)
NF ATACR

 

[Graham]

.308 tumbling at (almost) a mile.

I was not there but he did send me a picture barraging about how his TR was having consistent hits at 1680. And he wasn't experiencing any bullet tumbling. So by my limited knowledge I was under the impression that a .260 would have much better chances than a .308 at these distances. What gives?

Was he watching a Magpul video on a mountaintop at the time he sent the pics?

 

[luvmy45]

Have not put my bullets on paper at a mile, but my hits on steel with my 308 at a mile, have been like the photo your friend sent you. Not hitting the plate sideways.

Depending on what your are shooting, you may be in the transonic transition at around 1500 and the bullet is not stabilized... once thru the transonic zone, the bullet stabilized again and straightens out... at least that is my understanding from various sources... I could be full of crap as well...

 

[BillyGoatMachine]

Was he watching a Magpul video on a mountaintop at the time he sent the pics?

I suppose he could have brought his portable dvd player along for motivation…

Have not put my bullets on paper at a mile, but my hits on steel with my 308 at a mile, have been like the photo your friend sent you. Not hitting the plate sideways.

Depending on what your are shooting, you may be in the transonic transition at around 1500 and the bullet is not stabilized... once thru the transonic zone, the bullet stabilized again and straightens out... at least that is my understanding from various sources... I could be full of crap as well...

If I understand you correct, the bullet could be tumbling around 1500, then re-stabilize and continue on it's merry way? Seems impossible??

 

[luvmy45]

I suppose he could have brought his portable dvd player along for motivation…





If I understand you correct, the bullet could be tumbling around 1500, then re-stabilize and continue on it's merry way??

Not sure if they are tumbling, per se, but wobbling and and not stabilized as they they come thru the sound barrier... if they are not going straight and they may hit point first but not being stabilized just fold over sideways when they hit... again, I'm not sure how to verify this, I don't have a high speed camera to capture a hit.

 

[BillyGoatMachine]

Not sure if they are tumbling, per se, but wobbling and and not stabilized as they they come thru the sound barrier... if they are not going straight and they may hit point first but not being stabilized just fold over sideways when they hit... again, I'm not sure how to verify this, I don't have a high speed camera to capture a hit.

I understand what your implying now.

 

[Graham]

.308 tumbling at (almost) a mile.

I understand what your implying now.

Great, because I thought he was making things up, so perhaps you can explain his implication to the rest of us.

Was your friend talking about getting consistent hits at 1680yards with transonic bullets?

 

[luvmy45]

At 1680 and 1760 you are way out of the transonic area of flight for the bullet with a 308... as I understand it.

Transonic definition: Severe instability can occur at transonic speeds. Shock waves move through the air at the speed of sound. When an object such as an aircraft also moves at the speed of sound, these shock waves build up in front of it to form a single, very large shock wave. During transonic flight, the plane must pass through this large shock wave, as well as contend with the instability caused by air moving faster than sound over parts of the wing and slower in other parts.

My hypothesis is that the transonic zone of bullet flight is very unstable, the bullet could be yawing as it flys coming thru this zone... once it comes thru the other side, I am thinking that it restabilzes and continues on at a more predictable flight path.

Shooting a mile with the 308 is completely doable... and repeatable, wind is another story... and it moves the bullet around a lot... my misses at a mile with my 308 are usually windage not elevation.

Again, this is just my experience with my gun and my load, and I'm just reporting what I'm seeing on the target.

If the OP was getting keyholing at around 1500, depending on his load, that could be in the transonic zone... ... his buddy that was shooting around 1600 with the 308... is past the transonic zone of most 308's and is my hypothesis the bullet has stabilized again and thus flying straight and impacting the target head on...

 

[Graham]

.308 tumbling at (almost) a mile.

Shooting a mile with the 308 is completely doable... and repeatable, wind is another story... and it moves the bullet around a lot... my misses at a mile with my 308 are usually windage not elevation.

Again, this is just my experience with my gun and my load, and I'm just reporting what I'm seeing on the target.

Wind must be moving that .308 bullet around a lot at a mile, eh?
.... In your experience. And on the target.
Hmmmmmm....

 

[luvmy45]

Your point?

I must be missing whatever it is your trying to imply... just come out and say it.

 

[Graham]

.308 tumbling at (almost) a mile.

Your point?

I must be missing whatever it is your trying to imply... just come out and say it.

You're making things up.

 

[luvmy45]

Got it.

Yes, I am...it's called my hypothesis. I'm testing what I know, and verbalizing it to see if its true. I'm open to the possibility that I am completely wrong. If you have the answer, instead of playing word games why don't you point me in the right direction.

 

[BillyGoatMachine]

Was your friend talking about getting consistent hits at 1680yards with transonic bullets?

He said he was getting hits and his impacts did not reflect a tumbling bullet. That statement and some pics.

You're making things up.

Ok, so now we know it's his best educated guess to my question. Since you seem so confident can you offer any answers to my question? Why are his bullets not tumbling, and mine are? Or am I just such a noob that I don't even deserve your knowledge, just your ridicule?

 

[RyeDaddy]

Different bullet designs react differently to transition. The design of your Scenars is different than the 175 SMK.

I am not a ballistician, but that COULD account for your bullets tumbling and his not.

I know from personal experience that Berger VLD's become quite unsettled when they go transsonic, while the Amax's are much more predictable by comparison(accuracy still suffers but I have not had Amax's impact sideways). I've compared 168's from a 308 in both those brands. No long range experience here with SMK's.


This would be a great question for Bryan Litz, haven't seen him post here in a while.

 

[Graham]

.308 tumbling at (almost) a mile.

Ok, so now we know it's his best educated guess to my question. Since you seem so confident can you offer any answers to my question? Why are his bullets not tumbling, and mine are? Or am I just such a noob that I don't even deserve your knowledge, just your ridicule?

I'm not ridiculing anyone and there's no explanation to give. Your friend is simply not telling you the truth.

If you have the answer, instead of playing word games why don't you point me in the right direction.

As to me not having quoted sources, this same topic has so saturated this board that criticizing me for not repeating myself, again, means that you haven't even cared to read about it here on the site you posted if on.

OP, he is not getting anything near consistent hits at 1680 with a .308 on a 24" x 24" target. He just isn't. Unless he's at 10,000 feet, but even then the target is too small. Consistent hits on a barn, maybe.

The Australians have done some wonderful transonic ELR with .308s at 1300, but four hundred more yards is a world away from that. And, MagPul marketing videos aside, Uncle Elmo can't get consistent hits with a .308 at a mile on any Sunday.

As to keyholing, not even the 168 SMK does it all the time. Same thing happens to any bullet. Going back through the sound barrier can cause the bullet to tumble, but what it wants to do is travel tail first, and sometimes they do that as well.

Luvmy45, there are more and other indications than keyholing which tell you that your bullets are subsonic, have run out of gas and no longer flying true. One of them, if you really were shooting at a mile, you likely mistook for wind in post number eight.

 

[BillyGoatMachine]

I'm not ridiculing anyone and there's no explanation to give. Your friend is simply not telling you the truth.

As to me not having quoted sources, this same topic has so saturated this board that criticizing me for not repeating myself, again, means that you haven't even cared to read about it here on the site you posted if on.

OP, he is not getting anything near consistent hits at 1680 with a .308 on a 24" x 24" target. He just isn't. Unless he's at 10,000 feet, but even then the target is too small. Consistent hits on a barn, maybe.

The Australians have done some wonderful transonic ELR with .308s at 1300, but four hundred more yards is a world away from that. And, MagPul marketing videos aside, Uncle Elmo can't get consistent hits with a .308 at a mile on any Sunday.

As to keyholing, not even the 168 SMK does it all the time. Same thing happens to any bullet. Going back through the sound barrier can cause the bullet to tumble, but what it wants to do is travel tail first, and sometimes they do that as well.

Luvmy45, there are more and other indications than keyholing which tell you that your bullets are subsonic, have run out of gas and no longer flying true. One of them, if you really were shooting at a mile, you likely mistook for wind in post number eight.

Thank you Graham. I do appreciate you taking the time to explain yourself in more detail. As far as my friend not telling the truth, I could see him getting excited an elaborating a bit as most people tend to do.


As far as my original question, I'm still wondering. Unless Rye is right, but his doubt leaves my question standing.

Why are his bullets not tumbling, and mine are? Especially when I though I was shooting a superior long range round. I'm wondering if the weight of the bullet comes into play at long range. Or maybe it's like you said, his rounds are striking tail first after tumbling.

 

[Graham]

.308 tumbling at (almost) a mile.

Why are his bullets not tumbling, and mine are?

Yes, some bullets, by design, transition better than others. But no way that all your better BC bullets are tumbling and all of his are not under the same conditions.

But then, a high BC does make for a bullet that flies poorly, so it may transition poorly as well.

The question does not remain a valid question because his information is simply not accurate, thus you do not retain an obligation to believe it all.

 

[luvmy45]

I'm not ridiculing anyone and there's no explanation to give. Your friend is simply not telling you the truth.

Luvmy45, there are more and other indications than keyholing which tell you that your bullets are subsonic, have run out of gas and no longer flying true. One of them, if you really were shooting at a mile, you likely mistook for wind in post number eight.

In answer to your question... yes I was at 1760 yards.

Now, if we are done with our pissing contest about the actual distance, and that you CAN hit a target, at a mile with a 308... maybe we can talk about what is actually happening to the bullet...

To the point... if the transition period of the bullet thru the transonic zone unstablize's the bullet, which I believe we all agree that it does, does that only cause the drift from right to left? From my observation... my misses at a mile, have been left and right, not up and down... which seems strange that only windage seems to be affected and not elevation.

I have moved on to a larger caliber for ELR work, but I still have some mile loads for my 308 to shoot... I'm thinking one last trip to the mile marker with the 308 to use these rounds up, with a focus on trying to gather more data is in order... as my nerd side has been piqued.

Graham, I would love some more information on the Australian research, I have not read Litz's book... maybe I should go get that and start there, but would enjoy any information you could point me to. I have tried various searches here on the hide, and to date I haven't found the magic words that come up with past threads that discuss this.

Thank you,

 

[Graham]

Of course you can reliably hit a target at a mile with a .308: At that distance I hit the earth every time.

You won't find the Australian research. And yes, Bryan's book is worthwhile, as is Dean Michaelis's for some of it. But theory is just that. It's important not to lock-in on one theoretical aspect of bullet flight at the expense of others that may have more of an impact on the shot.

 

[BillyGoatMachine]

The question does not remain a valid question because his information is simply not accurate, thus you do not retain an obligation to believe it all.

What I do believe are the pictures of his targets and mine. Simply because I doubt he photoshopped them upon arriving back home before sending them. So by going off of the pictures alone, and no verbal information from me or my friend, the pics still show his rounds impacting straight on, and mine tumbling. That's still my question but I do understand how you cannot give a definitive answer because of elaboration and not having all the facts. I hope I am not annoying anybody with this post, but if I am just let me know. I can then crawl back into my noob womb and continue to try and figure things out on my own. Or I should have posted this in the correct Forum: Sniper's Hide Stupid Marksmanship Questions. I just found it and maybe I belong in there and not in the ELR forum.

If it helps? I was shooting at 685ft above sea level. Roughly 73 deg. Latitude 40, heading 346. Absolutely no wind at my shooting position. My kestrel wouldn't even move. I couldn't believe my luck that day for shooting this distance for the first time. There could have been a mild 2-3mph at the target, moving left to right.

As far as his conditions, He was outside of Medford, OR. Mild conditions. He mentioned a very light wind. I don't know the elevation or the exact temp but he definitely wasn't at 10,000ft.

Of course you can reliably hit a target at a mile with a .308: At that distance I hit the earth every time.

That would be a pretty good sig line

 

[Dubtown77]

Interesting!

 

[Lowlight]

Why don't you put paper out there... next to your steel, you can hit your steel with 1 shot then move immediately and fire your shots at paper. (Piece of cardboard.

I guarantee there are elevation issues with your bullet... it's not all wind, it just looks that way. You are a mile away after all.

5 hits out of 20 shots is luck, like the magpul video with something like 36 tries if my sources are to be believed. That is not consistency on any plane of existence. That is a blind squirrel getting lucky due to persistence and not consistency.

Saying, transonic over and over doesn't make you sound like you know what you are talking about, it's means you don't know the difference between "transonic" and sub-sonic. One happens like crossing the line in the road the other is everything else. So, here is an experiment with ranges you can control better... take a sub sonic 308 round and shoot it to 800 yards. See what happens with both your windage and elevation. (And sub sonic loads tend to be more consistent.) if you are loading your 260 you can load a sub sonic round and try it too. I think you'll find the biggest difference is the weight... conditions into the sub sonic region will blow the lighter bullet around much more than the heavier one.

Finally, don't confuse having an longer max effective range with having a better sub sonic range. If max effective on the 308 is 1000 yards, and your max effective on the 260 is 1200 yards, that doesn't mean it will be better at 1800 yards. (Clearly, 5 hits out of 20 is was of good ammo) The heavy bullet when lofted up and floating down has a bit more weight too it, so it might appear to work better, but work in this case is a highly subjective. You're Muzzle Velocity will cause huge elevation issues at ELR Ranges, unless your 308 bullet is in the single digits with your SD / ES numbers you're elevation is off and you don't know how far until after the bullet is shot. this is ELR 101... your muzzle velocity spread matters. On top of your normal accuracy, and we all know shooting 1/2 MOA at 600 yards don't mean you are shooting a 1/2 at 1000 yards, let alone in the sub sonic region. It always makes me chuckle when guys without a shred of formal instruction or understanding begin submitting "theories" on what is happening down range with all they have is a "rock" or piece of steel 1 mile away. Been posted before but here is a Gunsite ELR slide that demonstrates your group dispersion and shot correction problems when considering such things as MV and Accuracy.

Did you hit at the top of your accuracy cone, the bottom, or center ? Which was it... was that round in the middle, left or right of that accuracy circle and what your practical accuracy cone at that distance... if you think 1 MOA I think you would be highly mistaken, even if the gun is a 1/2 MOA shooter at supersonic ranges.

At Gunsite we tested bullets for vertical spread on paper at 1500m. These were well performing 338 bullets, I managed to keep factory 285s within 6 inches of vertical on target. However I did completely ignore my windage to concentrate on my elevation. The results were something like 20" of windage spread because I just held center and fired. So imagine a bullet designed to be shot that far, and what we were doing with this test. Shooting Paper at 1500m. If you're just lobbing rounds at at a steel target how do you expect to be consistent in any way, or even know what consistent is looking at something 1 mile away, with no real point of reference. It's highly deceiving because of the extreme angle the bullet is falling. If you are not sure about this, look at "Danger Space" and understand at a 1000 yards with a supersonic bullet, something like 10 yards plus or minus is your window. Further it just shrinks, so you can't really tell.

 

[paraman1]

I actually know a number of guys including Luvmy45 who have shot his clubs mile shoots with the lowly .308 and other subpar calibers and they are indeed hitting the targets out there . Is it the best tool for the job ? Hardly , but they are doing it , not every round but enough that I don't want to stand out there and let them shoot at me .

I am not quite sure why anyone feels the need to call him a liar unless they have gone out and tried it themselves .

 

[Lowlight]

I have done it, and I have also watched a shooters try it in a class by putting a man sized target out there, and know exactly what the results were...

So for all of us... Define: HITTING THE TARGETS

One round out of 10, 3 rounds out of 20, 5 rounds out of 30... what is hitting the target in this case.

 

[Graham]

.308 tumbling at (almost) a mile.

I am not quite sure why anyone feels the need to call him a liar unless they have gone out and tried it themselves .

The problem with BTDT is that it's only relevant to one's credibility when it causes a type of learning not available to anyone else.

Otherwise the only credential it gives is that you were a victim of circumstance.

Or, same analogy, I don't see why anyone feels the need to correct a post about terminal ballistics if they've never been shot.

 

[softcock]

..." My target last week. In the lower left you can clearly see 2 bullet strikes that appeared to have hit sideways. I even found a complete 260 pill with a dent in the side of it as it appeared to have struck the top of the steel as it tumbled to the target. I think a few shots might have hit straight on along with the sideways hits ".
-
I dont really know shit but your talking about almost a mile with Non-Mag. Cals. & ( At Those Ranges ?) . could the bullets that hit sideways have been just a little low on target & skipped into the plate ? making it appear that they were keyholing .
Man, Cal. & Bullet weight & RPS/revolutions per Second @ that range is different with all things ballistic . I think your worrying and putting to much into it .
.

 

[BillyGoatMachine]

Lowlight, thank you for coming in here and participating with your knowledge. Every bit helps me understand a little bit better even though I have a long ways to go.

..." My target last week. In the lower left you can clearly see 2 bullet strikes that appeared to have hit sideways. I even found a complete 260 pill with a dent in the side of it as it appeared to have struck the top of the steel as it tumbled to the target. I think a few shots might have hit straight on along with the sideways hits ".
-
I dont really know shit but your talking about almost a mile with Non-Mag. Cals. & ( At Those Ranges ?) . could the bullets that hit sideways have been just a little low on target & skipped into the plate ? making it appear that they were keyholing .
Man, Cal. & Bullet weight & RPS/revolutions per Second @ that range is different with all things ballistic . I think your worrying and putting to much into it .
.

No real chance the bullets were skipping to the target as the ground was extremely soft with the previous 3 days of rain. Also the ground had a decent layer of topsoil and fluffy grass. The only thing I was worrying about was why a superior long range caliber could have been performing worse at these extreme ranges. But LL's explanation of how the ballistically superior bullet might not perform better in the subsonic realm makes some sense. Looks like I won't be wasting any more of my .260 reloads past 1200. I'll leave that for my .338 SRS.

 

[softcock]

Man a solid 1200 yard .260 is no slouch .
Don't feel bad . my 300 wm with 190 vld's / 2925 vel. / 11.25 twist, hits the wall ( for me ) so to speak @ around 1500 yrd. .
The vel. & twist I send those bullets is strong at 1300 +, but I really noticed it all of the sudden open-up group & erratic struggle when I start pushing 190 VLD's to the 1500 yrd. mark .
.

 

[BillyGoatMachine]

Man a solid 1200 yard .260 is no slouch .
Don't feel bad . my 300 wm with 190 vld's / 2925 vel. / 11.25 twist, hits the wall ( for me ) so to speak @ around 1500 yrd. .
The vel. & twist I send those bullets is strong at 1300 +, but I really noticed it all of the sudden open-up group & erratic struggle when I start pushing 190 VLD's to the 1500 yrd. mark .
.

Ok, maybe 1200 is a bit optimistic on my part for the .260. I just know I won't even try at 1200+ anymore. I've got a great 1050y spot I'll try it at next. Previously I was shooting my .308 at the 1050 with a 50% hit ratio on 24x24" steel. But luckily that day my Kestrel wind meter wouldn't even register a breeze and I was still only hitting it half the time. Again like LL mentioned, the velocity spread in my reloads has a huge impact on hits or misses. My reloads vary in between 10-40 fps difference which will open up the elevation spread in a big way. I guess I just have to keep shooting to learn the rifle's limits, and mine