Barrel length vs. Accuracy

[ipscmaster]

Is their any correlation between barrel length and accuracy? I am in the process of building a new rimfire and I can't decide what length barrel. Most target rimfires have long (27--28 in) barrels and I am wondering if that is just intended for iron sights and longer sight radius , or is a longer barrel more accurate ? I know some of you more experienced shooters will have more knowledge than I about this .
Thanks for any input and experience. ipscmaster

 

[TOP PREDATOR]

Re: Barrel length vs. Accuracy

http://www.snipershide.com/forum/ubbthreads.php?ubb=showflat&Number=2137639#Post2137639

there's chuck hawk article a bit lower in that thread.

most of what i seen and experienced, anything over 17"ish is advantage intended for iron sights and longer sight radius, and not much in the way of accuracy.

 

[Boomholzer]

Re: Barrel length vs. Accuracy

Generally speaking, practical barrel length has a factor in velocity and not accuracy. However, velocity at range determines drift and accuracy relative to environmentals. The more push from a higher powder charge (relative to center-fire) requires adquate barrel length to achieve max muzzle velocity (MV). Shorter barrels, per profile, can be less picky with tuned load due to rigity and harmonics in shorter length.

I have not played around with .22lr MV on the chrono relative to factory offerings or different animals. I mostly shoot standard velocity or target .22 pills. 21" on a Lija/Sako has no range benefit over a long CMP 40x. From my knowledge, 18 inches in barrel length should be adequate for any .22rimfire max MV. I think our assumptions are correct in added barrel length both for mass/stability and palma-ish sight radius.

 

[Jeepocabra]

Re: Barrel length vs. Accuracy

16 to 17 seems to be the optimal length for 22 velocity with most loadings. The hyper velocity loadings are probably diffrent. If yout shooting a .17hmr or hmr2 then I don't know the lengths for for optimal burn.

 

[Jeepocabra]

Re: Barrel length vs. Accuracy

As far as what length to get if you are going scoped then get a short barrel in my opinion. Even if going iron sights then max length I would use would be 22". I like short and handy.

 

[Situation Normal]

Re: Barrel length vs. Accuracy

There's a point in all barrels where the maximum velocity has been achieved, and any extra leagth is just friction slowing the bullet down. In "most" 22's that's roughly in the 16"-18" range.

That said, most of those 27"-28" barrels were designed primarily for an open/aperture sight set up where the added length is a huge bonus in sight-radius.

I shot a 28" barrel CZ 452 Ultra Lux on a four position league and loved it in the prone, sitting, and kneeling positions, but hated it for the offhand position. I felt that the added length hurt my scores by "tossing" my rounds before the bullet left the barrel. A product of my poor follow through skills.

What are you looking for?

 

[Greg Langelius *]

Re: Barrel length vs. Accuracy

Good points. I conjecture that this could be carried for other steps.

If you're shooting with a scope and Std Velocity ammo, the 16"-17" bore length is probably optimal.

But the peak velocity may or not be the best attribute of a given load.

Going with a longer barrel might result in a lower velocity, and this might better ensure the round stayed subsonic beyond the muzzle.

Adding more bore length again might even make more brands of ammunition eleigible for subsonic performance. (i.e 'shoots nice, but it's just too marginally fast..., etc.').

If you're using subsonic and irons, a larger bore unrifled extension (commonly called a 'bloop tube' after the sound effect it adds) can be employed to extend the sight radius.

Overall sight radius length should be figured to adjust sight click increments precisely to common (i.e.1/2MOA or 1/4MOA, etc.) POI change increments at the intended distances.

Typically, a shorter barrel is comparatively stiffer, and should reduce harmonic swing; but in practice, some bets just never pay off as expected.

Greg

 

[Larry in SD]

Re: Barrel length vs. Accuracy

I have a Ruger K77/22VBZ in .22 LR. This rifle started life out with a 24" Factory Ruger Barrel. I had done quite a few modifications to this rifle to gain accuracy and was more than pleased with the results. One day I was handling a different Ruger 77/22 with a 20" Barrel and thought the handling qualities were much better with the shorter barrel.

With that said I went to my local gunsmith and had the 24" Barrel on my Ruger K77/22VBZ shortened and recrowned to 20". I did see enough gain in accuracy to make this worthwhile. Since this is a Hunting Rifle for Small Varmints I generally shoot HiVelocity Hollow Points and was surprised to see a 50 FPS increase in velocity with the barrel shortened 4".

On a different note I had a T/C Contender Super 14 .22 LR Handgun. This barrel with the same HiVelocity Hollow Poitns used in the above Ruger consistantly produced up to 100 FPS higher velocity averages, and was a bit more accurate than the above Ruger.

However there are trade offs, ie too much of a good thing. My Ruger MKII 5 1/2" Bull Barrel is super accurate but not in the same league as the above Ruger Rifle or Contender Handgun, and the average muzzle velocity with the same ammo is 200 to 300 FPS less.

Larry

 

[longguntoter]

Re: Barrel length vs. Accuracy

Barrel length, at least with a rimfire round that is, is not quite as important than with something like a .300 WinMag would be in a centerfire.