Shorter barrel is more accurate thread help.

[ERdept]

I"m trying to tell someone who believes that the longer the barrel the more accurate the rifle.

I understand magnums may need more length, but for the .308, I"m tryng to find the post where they used a hacksaw to cut the barrel and the rifle shot fine.

Or any other post in which the barrel chop on a .308 from 26 inches to 20 or 22 did not affect accuracy.

 

[WRM]

Re: Shorter barrel is more accurate thread help.

Shorter barrel w/same contour = more rigid, so theoretically more accurate....

Here's a Dan Lilja article on the subject:
http://www.riflebarrels.com/articles/barrel_making/rigidity_benchrest_rifles.htm

Cheers,

Bill

 

[JJones75]

Re: Shorter barrel is more accurate thread help.

If you cut the barrel off with a hacksaw it ain't gonna shoot fine!!

You will need to have it recrowned for certain , but like the other poster stated if you cut the barrel down it will get progressivly stiffer as it gets shorter , in theory a stiffer barrel is more accurate (but their are other factors that play into accuracy)

If you shooting factroy ammo out of a 308 then a 20" barrel is all thats needed the velocity gain going with a 26" will be slim likely under 100fps but the size of the weapon will seem ALOT bigger.

But if your trying to run heavy bullet out of a 308 or arun the lighter ones out as fast as possible then a longer barrel will be benificial as you can taylor your powder burn rate to take advantage of the added barrel length.

 

[ERdept]

Re: Shorter barrel is more accurate thread help.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: JJones75</div><div class="ubbcode-body">If you cut the barrel off with a hacksaw it ain't gonna shoot fine!!

You will need to have it recrowned for certain , but like the other poster stated if you cut the barrel down it will get progressivly stiffer as it gets shorter , in theory a stiffer barrel is more accurate (but their are other factors that play into accuracy)

If you shooting factroy ammo out of a 308 then a 20" barrel is all thats needed the velocity gain going with a 26" will be slim likely under 100fps but the size of the weapon will seem ALOT bigger.

But if your trying to run heavy bullet out of a 308 or arun the lighter ones out as fast as possible then a longer barrel will be benificial as you can taylor your powder burn rate to take advantage of the added barrel length. </div></div>

Yes, I know all this.

Now, I'm trying to find the post in which the barrel length of a rifle of 20 or 22 inches was found to be accurate vs a 26 inch barrel.

 

[Victory]

Re: Shorter barrel is more accurate thread help.

Here you go.
http://www.tacticaloperations.com/swatdec2000/index.html

 

[ERdept]

Re: Shorter barrel is more accurate thread help.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: victory</div><div class="ubbcode-body">Here you go.
http://www.tacticaloperations.com/swatdec2000/index.html
</div></div>


Exactly, Thanks you're the man, man.

 

[Victory]

Re: Shorter barrel is more accurate thread help.

No problem brother.

 

[Jicko]

Re: Shorter barrel is more accurate thread help.

Is shorter barrel more accurate? Or is longer barrel more accurate? I don't know for shorter distances, but for longer distances, or for max distance, you'll need a MV that brings your particular load/bullet above speed of sound @ your max distance.

It is all about what MV you are going to get out of your barrel, and the longest distance that you would like to shoot.

You also get higher MV out of high quality custom barrels than you can get out of a loosely spec'ed factory barrel of the same length.

So, barrel length isn't everything.

For example, you would need about 2600fps MV for your 175SMK to get to 1000m(1100yds) and stay above the speed of sound (1125fps) at sea level, with 68F. Now, you should consider giving yourself some margain for the temp to go lower and the ES of your ammo, etc...

So, as long as your barrel will give you the MV + margain.... then potentially, the shorter the better...

 

[RH4540]

Re: Shorter barrel is more accurate thread help.

I had a 24" barrel on one of my AR15s cut down to 17" to use for 3-gun, and accuracy got much better.

 

[clmayfield]

Re: Shorter barrel is more accurate thread help.

Varmint Al did a similar analysis to the Lilja one with similar results here: http://www.varmintal.com/aflut.htm

The article is about fluting, but it discusses barrel length and diameter and the relation to stiffness.

It should be noted that the stiffness dampens the amplitude of vibrations... theory has it that there is an optimal length at which the vibration wave is minimized. Rimfire folks have taken advantage of this for some time by using tuners... basically, a weight on the muzzle end of the barrel that you can move towards or away from the breech. They can make some really whippy-looking barrels that are dead accurate with a tuner... This has gone on for 10 years with BR rimfire and hasn't really caught on for BR center-fire yet.

 

[WRM]

Re: Shorter barrel is more accurate thread help.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Carter Mayfield</div><div class="ubbcode-body">... basically, a weight on the muzzle end of the barrel that you can move towards or away from the breech. They can make some really whippy-looking barrels that are dead accurate with a tuner... This has gone on for 10 years with BR rimfire and hasn't really caught on for BR center-fire yet. </div></div>

I suspect that is because we are able to tune the node by varying ammo parameters (charge weight, bullet selection, seating depth), whereas rimfire shooter have to tune the gun to the ammo. If shooting factory ammo, Browning's brake/tuner would do the same thing. Adjusting the moment of inertia....

It may not be that the heavier barrels "dampen" more (or differently) than light barrels, but rather they have less overall deflection, due to the increased stiffness.

Cheers,

Bill

 

[dar1246]

Re: Shorter barrel is more accurate thread help.

I think alot of the length of the barrel will be for the appliation you are going to use it for. Longer distances a 26" barrel get you more muzzle vel. I have a 20" 308 and a 24" 308 both shoot extremely good. Barrel length is a option for the application of use not is one more accurate than the other.

 

[ERdept]

Re: Shorter barrel is more accurate thread help.

Rabid thread. lol

 

[clmayfield]

Re: Shorter barrel is more accurate thread help.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: WRM</div><div class="ubbcode-body">
I suspect that is because we are able to tune the node by varying ammo parameters (charge weight, bullet selection, seating depth), whereas rimfire shooter have to tune the gun to the ammo. If shooting factory ammo, Browning's brake/tuner would do the same thing. Adjusting the moment of inertia....

It may not be that the heavier barrels "dampen" more (or differently) than light barrels, but rather they have less overall deflection, due to the increased stiffness.

Cheers,

Bill</div></div>

We use the word "tune" in both places, but the similarity pretty much ends there. The barrel harmonics are based on the gun geometry, not the load. When you switch .22LR ammo, you don't need to retune the tuner... at least not based on what I have read.

I think we are saying the same thing on deflection... there is less of it on a big heavy barrel... which is the same as saying the amplitude of the wave smaller... and importantly, there is less barrel droop to begin with, which also means less amplitude (less starting deflection).

 

[lfagan]

Re: Shorter barrel is more accurate thread help.

I need some help.....I read another thread recently concerning .308 barrel lengths and can't seem to locate it now. The thread centered around a rifle course being held out in the desert and they were cutting the barrels down with a Dewalt power hacksaw. It was a fairly interesting read. Can anyone point me to that thread?

Found it...
http://www.sniperschool.com/barrel-length-revisited


Thanks,
Len

 

[dar1246]

Re: Shorter barrel is more accurate thread help.

You dont lose to much speed in a 308 by cuting the barrel. I think because of case design. Most of the powder burns in the case rather than down the throat of the barrel. Therefore you have a longer barrel life. I think that is what I understood.

Montana marnie would be a good person to ask. He seems to be pretty knowledgeable about this subject.