No "right" barrel length?

[south]

Hi all,

First posts here so be gentle on a learning shooter

I see there is a big difference in the barrel lengths offered in the same calibre. Like .308 comes in anything from a 16" barrel scrub rifle to 30" barrel target rifle.

I know there are different loads but nearly double the barrel length seems like a huge difference?

I suppose I would have thought there would be quite common length somewhere in the middle and a few on the outsides for specific purposes.

Or does the barrel length just not matter so much?

[Blu333]

If you have a little bit of time read this link, it should answer a few questions

http://www.thetruthaboutguns.com/2013/1 ... -accuracy/

[Seconds]

Or does the barrel length just not matter so much?

Short answer, for most shooters I'd say no.

For hunters if a rifle shoots 1.5 or so MOA that's all it needs to do. 100fps more or less velocity from a barrel being slightly longer or shorter than ideal won't change anything.

For average joe doing target shooting for fun it's pretty much the same story. You'd need to be taking your target shooting very seriously for it to matter or be trying to get every last FPS out of it for looong range shooting.

Still read that article though, plenty of good stuff

[cruze82]

cheers blu333 had not read that one before, not a bad read

[SendIt]

Shopping for your first rifle, South?

What kind of shooting will you be doing?

[south]

Thanks everyone for the info so far.

That article explained a lot Blu

Yes my first rifle, SendIt. I'll be getting a hunting rifle, probably in .308 too like I've used in my question.

Any extra info around that specifically would still be welcome

[Hucka]

Most if not all of this is may be covered in that link, TBH I didn't read the whole thing, but here is the issue in a nutshell.

Ideally you want the powder to finish burning right as the bullet exits the muzzle.

If the barrel is too long the bullet will start to slow from resistance in the barrel once the force from the powder burning is declining. If the barrel is too short powder is still burning once the bullet has left the barrel and it just blasts out as wasted energy. In either case some velocity is lost.

For your hunting this isn't going to mean jack. I did a quick scan of the article and pulled out these figures for one of their tests done with a 168gr hornady. Two of the barrel length and velocity figures quoted from the test are:

26" barrel - 2,705
18" barrel - 2,650

The animal on the receiving end isn't going to know the difference between getting hit by a 168gr bullet from the 26" barrel moving at 2,705 fps or one moving 55fps slower from the 18" barrel.

Choosing the 26" barrel for the extra velocity in this case would make no sense at all.

Of you're hunting in the forest or any dense environment where the longer barrel is likely to get caught, choosing the shorter barrel would make sense and there is a clear advantage for handling.

[mausermate]

Note velocity differences between barrel length increases as the bullet weight decreases, in some but not all of the loads. It indicates if you intended to use 168 grainers and heavier for hunting you would find little benefit in a longer barrel in a 308. However, if you used 150gr or even 110 grain bullets the differences are significant and worth a closer look. According to the article.

[Hucka]

Yeah, I just used 168gr as the example because that's the first bit I scrolled to. That's not everything there is to it.

Barrel length, bullet weight and powder charge are all part of it. Change one and you effect the rest.

It's not all about barrel. Longer barrel with heavier powder charge might be perfect.

Just used the 168gr as an example to show how for OP it doesn't matter anyway in his situation IMO.

[handofcod]

I once read that longer heavier barrels can be more accurate in field use due to the pendulum effect making it move more slowly when aiming. Think it was in a US marine Corp manual about ideal rifles.

[Aussier]

For hunting... Whatever.

Buy the rifle that feels best and that you like the most.

Forget matching a barrel length.

[lole]

I once read that longer heavier barrels can be more accurate in field use due to the pendulum effect making it move more slowly when aiming. Think it was in a US marine Corp manual about ideal rifles.

I've read something similar. I think the trick is you have to do it in conjunction with that funny full extent of the left arm to steady it though. Like you're trying to reach out and touch something with your off hand.

Might have some benefit for life and death shooting, feels weird doing it on a hunt. Like trying to be tacticool for the deer

[keg]

We just shortened a barrel for a Thompson Encore from 26" to 20" for a customer. His report was the barrel's groups went from 5" at 300 yrds to well under 3. It is more than likely because we take a lot more care to get the crown square and centered with the bore than the manufacturer. His report also was the gun was a heck of a lot more handy with 6" of excess barrel removed.

[zook60]

http://www.tacticaloperations.com/SWATbarrel/

[zook60]

We just shortened a barrel for a Thompson Encore from 26" to 20" for a customer. His report was the barrel's groups went from 5" at 300 yrds to well under 3. It is more than likely because we take a lot more care to get the crown square and centered with the bore than the manufacturer. His report also was the gun was a heck of a lot more handy with 6" of excess barrel removed.

Going from 26-20" the accuracy gain would have been due to the better harmonics of the barrel. A shorter barrel in the same thickness will be more accurate due to it being stiffer. You will get less barrel wip when the rifle is fired. But if it had a poor crown you would have also been doing him a favour.

[south]

Thanks all round guys.

Time to learn about crowns now after what's been said