AR 10 - 16 inch barrel - seems kinda short

[cmshoot]

I've got an 18" JP Enterprises LRP-07 in .308, and a 16" DRD Tactical M762 with a Proof Research barrel. The JP rings steel at 1238yds with no issues.....that's the furthest I've tried to run her.

I've had the DRD Tactical M762 out to an easy 1,000yds. Again, that's the furthest I've tried her.

 

[GAgunLAWbooklet]

I have an 18" barreled .30-06. It's not terrible. Louder than an M1 Garand or Weatherby Mark V in the same caliber, sure. But then, you'd expect an 18" barrel to be louder than a 22" or 24" barrel.

Now, the next issue is velocity loss. As others have said above, the loss "per inch" of rifle barrel varies by caliber and how long we're talking. There's more of a difference between 16" and 18" than there is between 20" and 22" barrels.
But it's still less than 50 f.p.s. / inch.

Will you fail to hit a target if your bullet's going 200 f.p.s. slower than if you'd been using a standard 20" barrel?
Will you only wound the deer instead of killing it cleanly? I doubt it.
But if you were shooting really long range, yeah, I'd say you'd want some more barrel on that rifle to burn more of the gunpowder and boost your velocity closer to normal.

 

[GAgunLAWbooklet]

As posts #9 and #10 above said, shorter barrels are NOT less accurate, when you're using a scope.
Longer barrels are more accurate when you are shooting iron sights, and more sight radius is better and makes for more precise aiming.

In fact, as a matter of physics, short barrels are stiffer, with less flexing or "whipsaw" motion of the muzzle as the bullet is moving down the bore, about to exit. Shorter = stiffer, and stiffer = more accurate.

 

[rockyfatcat]

As posts #9 and #10 above said, shorter barrels are NOT less accurate, when you're using a scope.
Longer barrels are more accurate when you are shooting iron sights, and more sight radius is better and makes for more precise aiming.

In fact, as a matter of physics, short barrels are stiffer, with less flexing or "whipsaw" motion of the muzzle as the bullet is moving down the bore, about to exit. Shorter = stiffer, and stiffer = more accurate.

Er not exactly. The weapon has harmonics that will flex and snap like a hose when you it violently lift and snap it. The real trick is timing the center of the oscillation to coincide with the bullet leaving the barrel.
This video will explain it better than I could.
https://wn.com/Sniper_101_Part_7_Rifle_Vibrations_Harmonics_Explained_Rex_Reviews

 

[mperry]

I immediately swapped my 16" for a lightweight 20".

 

[ReservoirDawg10]

Er not exactly. The weapon has harmonics that will flex and snap like a hose when you it violently lift and snap it. The real trick is timing the center of the oscillation to coincide with the bullet leaving the barrel.
This video will explain it better than I could.
https://wn.com/Sniper_101_Part_7_Rifle_Vibrations_Harmonics_Explained_Rex_Reviews

He was touching on a different aspect than harmonics.

 

[greg vess]

I built a 18 inch AR10 and it's perfect. Accurate as any off the shelf bolt gun and you get a little BC out of the 18. Don't get me wrong if weight is the issue 16 is fine for hunting and probably the best length for that purpose. I chose a bull barrel for accuracy and anything over that length is just to heavy. A 16 inch bull barrel would be a good choice if you are dead set on a 16 inch job. Yeah you will sacrifice some velocity but up to 500 yards it won't make a whole bunch of difference when it comes to dropping a deer. The bull barrel will cut down on barrel whip and you will still retain the accuracy the 308 is known for. A longer, lighter barrel will give you more velocity but at the expense of accuracy. Not an ideal trade off IMHO.
Not to mention when you add a good muzzle brake it will add a couple of inches to your build. Sig makes a 16 inch 7.62 as does DPMS so it's not a unicorn. It just depends on what you want to achieve out of the gun. Maximum velocity or accuracy.
I can't think of any game in the lower 48 that a 16 inch 7.62 won't drop.

 

[GAgunLAWbooklet]

16" barrels don't have nearly the same oscillation or "harmonics" than longer barrels do, such as a typical 20" would, given the same profile and contour. Therefore, the shorter barrels are stiffer and are more forgiving if you don't get the barrel harmonics just right. In other words, there's less of an inherent problem for you to try to overcome.

https://www.shootingsoftware.com/barrel.htm

 

[rockyfatcat]

He was touching on a different aspect than harmonics.

I guess you didn't bother to watch the video. It explains nodes and harmonics as it applies to rifles

 

[ReservoirDawg10]

I guess you didn't bother to watch the video. It explains nodes and harmonics as it applies to rifles

I am perfectly understanding of harmonics and nodes. Surprisingly enough, there are other aspects to barrel profiles and lengths other than simply harmonics. Hence the reason for different barrels profiles. His comments were not an all encompassing discussion on ballistics, just one aspect to consider. Heavier, shorter barrels combat barrel droop and whip/lash, whatever you want to call it. You still need to load your ammo, tension your action, etc, etc, etc, to make your rifle rifle more accurate and to tune the round exiting at the same point.