Good(?) Article on Barrel Length

[F23]

Hello everyone,

I’m still in what I would call the initial stage of learning about long range shooting, and came across this article. If it’s all true, and I have no reason to believe that it’s not, I think it would be a good read for other people in the same learning phase as me. Anyone with more experience want to give it a read, and possibly move it to a more appropriate section?

http://www.wideopenspaces.com/the-truth-about-barrel-length-muzzle-velocity-and-accuracy/

Thanks Everyone,

F23

 

[MtnCreek]

I just looked at graphs and read the conclusion. I saw some numbers that seemed odd...

Bolt Action section would be the place to get better info than here. FWIW, Longer = More Velocity = Less Drift. Also = Weight and Bitch to Carry.

 

[spaniel]

I really didn't think it was a good article.

So by halving the barrel length it resulted in a 15% reduction in velocity and they pretend this is insignificant. For long range shooting/hunting we move up to magnum cartridges to get ballistics and energy at extended range, and get this or less improvement over the cartridge we are choosing. 15% reduction in velocity is NOT insignificant to the long range shooter/hunter.

Also, they tested only one cartridge, one which is fairly moderate and therefore less sensitive to being shot out of a short barrel. Try that same test with a 338 Edge or 28 Nosler and report back.

Finally, the issue of barrel length and accuracy. Not sure why they think it's a standard assumption that barrel length affects accuracy. As long as the bullet is stabilized it's been a long time since I've heard any real support for this concept. It does, however, apply in settings where iron sights are being used and a short barrel means a short sight radius.

There are settings where understanding the magnitude of the tradeoff is meaningful. If you know you'll be hunting hogs or something in close cover and not shooting over 100-150 yards, then it makes sense to have an easy-to-carry short barrel rifle because long range ballistics are irrelevant.

 

[F23]

@spaniel Thanks for the reply! I was thinking the same thing with regards to him kind of brushing off 15% velocity loss, and also how he so casually says that it shouldn’t affect the difficulty/necessary precision of wind calls...

I hadn’t thought of the use of .308 making a difference, but that absolutely makes sense.

F23

 

[mdmp5]

The author of the article sounded a little amateur to me with some of the things he said. Saying 2300 is hardly slow is just a pretty dumb statement. You’re not gonna come across many, if any precision rifle loads that shoot that slow. Also, giving this sort of merit to fliers as completely normal; I don’t agree with that either. Plenty of rifles are capable of ½ moa or better without some “normal” 1 moa flyer fucking it up. If I’m on point and my rifle is throwing shots, my load or my rifle isn’t working like it should

 

[Rthur]

A 308 isn't the ideal cartridge to test on barrel length.
Flyers could be the shooter as well as the rifle's fault.
Accuracy/barrel length in these test only proved a sample of one.
Some SD/ES info on the loads, factory and reloads, would be pertainant.
My conclusion is this shooter/rifle combo does better inside 540 than further.

R

 

[MtnCreek]

I didn't notice any obvious flyers. I did like that MOA Ball at 900 w/ 2400 MV. :-D

 

[Fig]

I think the article is essentially correct in a very basic way, but I'll bet few who post here have the false assumptions/beliefs they're referencing. I've never heard anyone who shoots or competes with me who thinks a longer barrel is "more accurate" as in a tighter 100 yd group. If you hand load you know it's easier to find a tune to a short barrel rifle than a long one, and the nodes are a lot wider (most of the time).

I think what they have to say about 5 shot groups is spot on, and a point made on SH often. If you get one of Bryan Litz's books and look into his WEZ system, and the supporting figures, the statistical part of rifle precision becomes crystal clear. Thinking of it as a "cone" is correct.

That's a good point about .308 not being the ideal cartridge to talk about long range, and as was pointed out when loading with H1000, Retumbo, Ramshot, etc. (slow powder to push a heavy bullet a long way) when you start cutting off inches of your barrel you're going to start getting a fireball of unburnt powder coming out the business end, and velocity is going to fall off FAST. It may still throw a small group at 100 yds, meaning absolutely nothing.

The last chart, "Average Radial MOA Compared", might be misleading for someone who doesn't shoot. The reason your group doesn't stay the same size proportional to range is because of environmental factors, period. If you did this test in space a .5 moa group at 100 would stay a .5 moa group at 1000. The reason it increases is because of all the exterior factors that either are or aren't being taken into account. No one's calculations, wind calls (wind guesses), and DOPE is perfect.