Short Barrel 308

[Warlord]

Hi all. I'm looking at picking up a 308 with a 16.5" heavy barrel. The rifle will be mostly a range toy with occasional hunting. I know I'll have less velocity than a longer barrel but I was wondering if there are other reasons not to go short? I only have 400yds max that I can shoot and the woods around here can get very thick so I was thinking the shorty would be a great idea. I assume with less velocity I'll have more drop out to 400 but maybe I can load some faster powders to try to reduce the disadvantage in speed. Thoughts?

 

[hatt]

Faster powders aren't going to help you. Slower powders are going to give you the most velocity in any reasonable barrel length. I don't really see the advantage of really short barrels on range toys or hunting rifles. 19-20 inch barrels are still pretty compact and don't give up much velocity in .308. If you just want a 16 inch .308 there's nothing wrong with it. It's plenty capable of doing what you want.

 

[JohnnyJohnson]

Had a short barrel like you're talking about in a Remington 600. Never again huge flame out of the barrel with every shot. Rebarrelled with a longer barrel and now its a much more enjoyable gun with a whole lot less muzzle blast.

 

[stockrex]

I have AKs in 16 inch barrels and ARs in 18

one word, LOUD,

I have a thunderbeast silencer for the AR, the AKs are sporterized so I have to live with the flame throwers.

I would suggest an AR from PSA.

 

[Cujet]

I always liked the overall performance of the 20 inch AR10 style 308. I have an LR308 in 24 inch heavy barrel and it's too long, too nose heavy for anything other than bench work.

However, I've really come to like the KelTec RFB 308 in 24. It's a very well balanced gun. If you can get over the unusual ejection system (that has no real downside for my type of use) I think it's worth considering.

The 18 inch version is super short:

Both are well armored guns by the cheek weld area.

 

[ironman_gq]

Not at those ranges, the loss of velocity only becomes an issue if your bullet is dropping below supersonic before it gets to the target. You will have quite a bit more muzzle flash so you might want to look into low flash powders

 

[JohnnyJohnson]

Originally Posted by ironman_gq
Not at those ranges, the loss of velocity only becomes an issue if your bullet is dropping below supersonic before it gets to the target. You will have quite a bit more muzzle flash so you might want to look into low flash powders


Even with an 18" barrel low flash powder myth is going to buy you very little. Been there done that.

 

[stockrex]

FYI:
I watched a youtube vid of a guy in Tx shooting 1000 yards with a 16 inch 308, he was ringing the steel target.

 

[hatt]

Originally Posted by stockrex
FYI:
I watched a youtube vid of a guy in Tx shooting 1000 yards with a 16 inch 308, he was ringing the steel target.

He would make more hits with a 20 inch.

 

[Warlord]

Ah good call on the muzzle blast. I hadn't considered that. Might make range days a bit less comfortable. 20 inches seems to be a good compromise.

 

[Driz]

Originally Posted by Warlord
Ah good call on the muzzle blast. I hadn't considered that. Might make range days a bit less comfortable. 20 inches seems to be a good compromise.



I wouldn't get excited about the difference in muzzle blast. You'll be wearing ear muffs anyways. It's more a personal choice thing than anything meaningful. It's probably a good idea to use the heaviest bullet you can if it's brushy where you're hunting.

 

[claluja]

44.2 IMR 4064 under 168 gr may get you 2540-2560 fps with 16-16.5" barrel in an AR10 if you can get that high without pressure issues. 43.0-43.2 XBR may be worth looking at also.

Are you talking gas or bolt?

 

[Ws6]

16" is plenty. Manage muzzle signature with a can. Enjoy.

 

[Warlord]

I should have mentioned I'll be looking at a bolt action. We can't really run suppressors up here but muzzle brakes are ok. I had a specific gun in mind that a local shop recently took in trade but I'm thinking I'll hold out for a bit longer barrel. None of the ranges are open now anyways.

 

[BrianSchulze]

Funny how many people assumed an AR style. They've really taken off. For $700 you can have a 308 (or 6.5) that will shoot 1 moa. But they are a little heavy. I've considered a 16 just for better weight balance.

You can get whatever you want, short barrel, long barrel, you will still have bullet drop at long range. The distance at which the bullet drops below supersonic (transonic?) is where it will get fuzzy.

Shorter barrels tend to be more accurate than long barrels. That is an indisputable fact.
Long barrels better for velocity.

Still, I would prefer 20" in a bolt gun minimum and 16 in a large frame AR.

Small frame AR? No limit....🤗

 

[762fermeandyou]

Originally Posted by hatt
Faster powders aren't going to help you. Slower powders are going to give you the most velocity in any reasonable barrel length. I don't really see the advantage of really short barrels on range toys or hunting rifles. 19-20 inch barrels are still pretty compact and don't give up much velocity in .308. If you just want a 16 inch .308 there's nothing wrong with it. It's plenty capable of doing what you want.


I have a DPMS style 20" 10 twist, 168/175 sierras, 43 gr varget gives me ~2650 ft/sec and plenty accuracy. I wouldnt go shorter.

 

[ABN_CBT_ENGR]

Originally Posted by Warlord
I assume with less velocity I'll have more drop out to 400 but maybe I can load some faster powders to try to reduce the disadvantage in speed. Thoughts?


No, not as long as the laws of physics apply but it is a commonly held belief but simply incorrect.

From the gyroscopic perspective a bullet cannot generate lift so it is null to the effect. ( tumbling, key holing, yawing makes it do weird things but do not generate lift). Only fins generate lift.

So the velocity in X ( speed of bullet along path alluding to distance) is independent and decoupled from the velocity in Y ( speed and pull of gravity relative to fall to earth)

There are factors ( external to the constants above) that WILL have a degree of effect thus giving the "illusion" that they are the same. Some of them are air density, aim trajectory V. linear datum trajectory, the muzzle distance to datum versus impact distance taking into account surface profile changes over distance then theres Newton's cannonball, Earth's rotation and a few others depending on how far one wants to dig into the science of trajectory.

At 400, I would not worry or be concerned.

 

[hatt]

Originally Posted by ABN_CBT_ENGR
Originally Posted by Warlord
I assume with less velocity I'll have more drop out to 400 but maybe I can load some faster powders to try to reduce the disadvantage in speed. Thoughts?


No, not as long as the laws of physics apply but it is a commonly held belief but simply incorrect.

From the gyroscopic perspective a bullet cannot generate lift so it is null to the effect. ( tumbling, key holing, yawing makes it do weird things but do not generate lift). Only fins generate lift.

So the velocity in X ( speed of bullet along path alluding to distance) is independent and decoupled from the velocity in Y ( speed and pull of gravity relative to fall to earth)

There are factors ( external to the constants above) that WILL have a degree of effect thus giving the "illusion" that they are the same. Some of them are air density, aim trajectory V. linear datum trajectory, the muzzle distance to datum versus impact distance taking into account surface profile changes over distance then theres Newton's cannonball, Earth's rotation and a few others depending on how far one wants to dig into the science of trajectory.

At 400, I would not worry or be concerned.
The longer the bullet takes to get to the target the longer gravity has to work.

 

[ABN_CBT_ENGR]

Originally Posted by hatt
The longer the bullet takes to get to the target the longer gravity has to work.


Not in this universe and relative to the physics and application aforementioned

 

[bsmithwins]

You can play around with power selection to get the most possible burning within the barrel length you do have, as opposed to commercial loads that are probably optimized for longer .308 barrels.

Faster bullet = less time to target = less drop, so you get better practical accuracy since range estimation becomes less important.

These guys did a barrel cut down test and found a average loss of 23fps for each inch of barrel lost: http://bulletin.accurateshooter.com/2015/06/308-win-barrel-cut-down-test-velocity-vs-barrel-length/

To put it in perspective, 30-50fps of velocity drop is about the difference between a gas operated self loader and one w/o a gas tap.

BSW