AR-15 Barrel Length for Competition

Shooter2675 · February 15, 2015, 05:08 PM

I am looking to build a new upper for my AR-15, as as much as I would like to build it in 6.5 Grendel, I would seldomly shoot past 500 yards so I don't see a need for it. .223 bullets are significantly cheaper and I can easily find the brass. I also already load for .223 so it would be easier for me.

What length barrel would be best? I have narrowed it down to two choices, a 26 inch or a 20 inch. I was looking to buy from John Holliger at White Oak Armament. For the 26 inch barrel I was looking at this barrel:
http://www.whiteoakarmament.com/xcar...64&cat=&page=1

For the 20 inch, I was looking at John's 20 inch 1x7 twist Shilen barrel. It can be found here: http://www.whiteoakarmament.com/xcar...cat=311&page=1

I would primarily use it for target shooting with a scope, but would also like to do some predator and vermin hunting with it. Do you think the extra velocity is worth it in the 26 inch, or is the 20 inch enough. What length are most guys shooting at the Camp Perry matches?

Thanks,

John

Mobuck · February 15, 2015, 05:37 PM

I've found that my bolt action 24" .223 offers 100 fps (or more) increase in velocity over a 20". You may find problems with 24" AR barrels if the maker doesn't drill the right size gas port. I took a dysfunctional AR upper in on trade a few years back. It had a completely incompatible gas system-carbine gas with a 24" barrel. So much gas was coming through the gas tube that the bolt would almost close and then cycle again-EVERY SHOT. I put an adjustable gas block on it and fixed the problem but it never should have been set up that way. Even a 24" with a rifle gas system needs to have some attention given to the "dwell time" between gas block and muzzle and appropriate sizing of the gas port.
Oh forgot to mention. If you do anything except shoot from the bench, a 24" AR is an ungainly, muzzle heavy monster.

Shooter2675 · February 15, 2015, 05:53 PM

The barrel I was looking at in 26 inches has an extended rifle length gas system. Is 26 inches bad for calling in coyotes and staying stationary?

John

Shooter2675 · February 15, 2015, 10:03 PM

How much extra velocity would I get with a 26 inch vs. a 20 inch?

John

Taco-XL · February 15, 2015, 11:10 PM

At that distance i dont think a 24-26 is needed. Increased velocity? Yes. But that doesnt mean increased accuracy. More velocity doesnt always mean more accuracy, especially at shorter distances. A shorter barrel may actually be more accurate as it does not suffer from as much barrel whip/harmonics as does a longer barrel. A longer barrel doesnt give you more accuracy directly. It gives more velocity in order to keep the bullet supersonic as long as possible and to reduce flight time. But as long as the round stays supersonic at the distance you plan to shoot, a longer barrel may not give any benefit.

Shooter2675 · February 16, 2015, 09:36 AM

Ok, thanks for your input. The farthest ranges I have around me are 600 yards, but there are some places (no ranges) where I could shoot safely to 1000 yards. The 26 inch barrel I was looking at is very heavy and I think very stiff. I like the idea of a 20 inch barrel but I'm a little hesitant only becuase I already have a 16 inch barrel 5.56 upper. In the future I may may build myself a 6.8 upper for hunting, so the 26 inch would really only be a target rifle. John at White Oak Armament sells both a 26 inch with made from a Wilson Arms (not Combat) blank, and a 20 inch made from a Shilen blank. Both are listed under the category High Power Competition. I know that is just a marking slogan, but he has lots of other barrels for hunting and plinking, so I think the contour of the barrels I listed are both stiff and heavy.

John

Jimro · February 16, 2015, 09:44 AM

What are most guys shooting at Camp Perry? The answer is both 20" and longer barrels.

High Power Service rifle shooters have been using 20" barreled AR's to shoot at 600 for years now. They are limited to 20" because of the service rifle rules.

High Power (match rifle class) have been using the longer barrels because it lets them mount the front sight further out and gain a small velocity advantage. When you are handloading for a match rifle, it isn't too difficult to come up with an accurate load as long as the barrel is decent quality.

If you are going to be using a scope exclusively, then either barrel will work, however I would recommend the longer barrel as it will have more mass and make spotting your own shot through the scope just a tad easier.

I hope this helps.

Jimro

Shooter2675 · February 16, 2015, 10:35 AM

Thank you Jimro. 26 inch barrel it is. When I get the funds together and buy the parts I will make a new thread detailing the new build.

John

kraigwy · February 16, 2015, 12:22 PM

Using 223 77 gr sierra bullets:

20 in 2650 fps SS 800 yards 10 mph drift 12.6 moa
24 in 2790 fps SS 850 yards drift 11.6 moa
26 in 2840 fps SS 900 yards drift 13.4 moa

SS being the point where the round becomes sub sonic
Drift is the MOA drift of a 10 MPH FV wind at the point the round becomes SS

Depending on how are you intend on shooting, I don't really see that much of an advantage of anything over 20 inches for an 223.

Shooter2675 · February 16, 2015, 12:45 PM

Like I said mostly matches and coyote hunting. I have several very long guns (26+ inch barrel) and I don't mind the length. To me 190 FPS is a good amount.

John

Jimro · February 16, 2015, 12:47 PM

kraigwy,

If you can get 2840 fps with a 75gr AMax bullet the SS transition doesn't happen until 1,000 yards. Unfortunately the 223 just hasn't ever come into its own as a 1k cartridge.

But since the OP is only worried about scoped shooting, the extra mass of the longer barrel (and longer torque moment because of muzzle mass) means less movement under recoil and faster back on target times. Things which have nothing at all to do with ballistics or accuracy.

Jimro

Shooter2675 · February 16, 2015, 12:58 PM

Yeah that's one of the reasons I like the 26 inch. Less recoil (it already has very little, and I don't want less recoil because I think there is too much) for faster follow up shots. If I am hunting with a shooting stick as I often do, the weight doesn't bother me and the faster follow up shot might help with that yote that tries to run.

John

February 15, 2015, 05:08 PM	#1
Shooter2675 Senior Member Join Date: August 17, 2013 Location: Western Pennsylvania Posts: 382	AR-15 Barrel Length for Competition I am looking to build a new upper for my AR-15, as as much as I would like to build it in 6.5 Grendel, I would seldomly shoot past 500 yards so I don't see a need for it. .223 bullets are significantly cheaper and I can easily find the brass. I also already load for .223 so it would be easier for me. What length barrel would be best? I have narrowed it down to two choices, a 26 inch or a 20 inch. I was looking to buy from John Holliger at White Oak Armament. For the 26 inch barrel I was looking at this barrel: http://www.whiteoakarmament.com/xcar...64&cat=&page=1 For the 20 inch, I was looking at John's 20 inch 1x7 twist Shilen barrel. It can be found here: http://www.whiteoakarmament.com/xcar...cat=311&page=1 I would primarily use it for target shooting with a scope, but would also like to do some predator and vermin hunting with it. Do you think the extra velocity is worth it in the 26 inch, or is the 20 inch enough. What length are most guys shooting at the Camp Perry matches? Thanks, John __________________ "Better to remain silent and be thought a fool than to speak and to remove all doubt." - Abraham Lincoln

February 15, 2015, 05:53 PM	#3
Shooter2675 Senior Member Join Date: August 17, 2013 Location: Western Pennsylvania Posts: 382	The barrel I was looking at in 26 inches has an extended rifle length gas system. Is 26 inches bad for calling in coyotes and staying stationary? John __________________ "Better to remain silent and be thought a fool than to speak and to remove all doubt." - Abraham Lincoln

February 15, 2015, 10:03 PM	#4
Shooter2675 Senior Member Join Date: August 17, 2013 Location: Western Pennsylvania Posts: 382	How much extra velocity would I get with a 26 inch vs. a 20 inch? John __________________ "Better to remain silent and be thought a fool than to speak and to remove all doubt." - Abraham Lincoln

February 16, 2015, 09:36 AM	#6
Shooter2675 Senior Member Join Date: August 17, 2013 Location: Western Pennsylvania Posts: 382	Ok, thanks for your input. The farthest ranges I have around me are 600 yards, but there are some places (no ranges) where I could shoot safely to 1000 yards. The 26 inch barrel I was looking at is very heavy and I think very stiff. I like the idea of a 20 inch barrel but I'm a little hesitant only becuase I already have a 16 inch barrel 5.56 upper. In the future I may may build myself a 6.8 upper for hunting, so the 26 inch would really only be a target rifle. John at White Oak Armament sells both a 26 inch with made from a Wilson Arms (not Combat) blank, and a 20 inch made from a Shilen blank. Both are listed under the category High Power Competition. I know that is just a marking slogan, but he has lots of other barrels for hunting and plinking, so I think the contour of the barrels I listed are both stiff and heavy. John __________________ "Better to remain silent and be thought a fool than to speak and to remove all doubt." - Abraham Lincoln

February 16, 2015, 09:44 AM	#7
Jimro Senior Member Join Date: October 18, 2006 Posts: 7,097	What are most guys shooting at Camp Perry? The answer is both 20" and longer barrels. High Power Service rifle shooters have been using 20" barreled AR's to shoot at 600 for years now. They are limited to 20" because of the service rifle rules. High Power (match rifle class) have been using the longer barrels because it lets them mount the front sight further out and gain a small velocity advantage. When you are handloading for a match rifle, it isn't too difficult to come up with an accurate load as long as the barrel is decent quality. If you are going to be using a scope exclusively, then either barrel will work, however I would recommend the longer barrel as it will have more mass and make spotting your own shot through the scope just a tad easier. I hope this helps. Jimro __________________ Machine guns are awesome until you have to carry one.

February 15, 2015, 05:37 PM	#2
Mobuck Junior member Join Date: February 2, 2010 Posts: 6,846	I've found that my bolt action 24" .223 offers 100 fps (or more) increase in velocity over a 20". You may find problems with 24" AR barrels if the maker doesn't drill the right size gas port. I took a dysfunctional AR upper in on trade a few years back. It had a completely incompatible gas system-carbine gas with a 24" barrel. So much gas was coming through the gas tube that the bolt would almost close and then cycle again-EVERY SHOT. I put an adjustable gas block on it and fixed the problem but it never should have been set up that way. Even a 24" with a rifle gas system needs to have some attention given to the "dwell time" between gas block and muzzle and appropriate sizing of the gas port. Oh forgot to mention. If you do anything except shoot from the bench, a 24" AR is an ungainly, muzzle heavy monster.

February 15, 2015, 11:10 PM	#5
Taco-XL Senior Member Join Date: January 6, 2015 Location: West Virginia Posts: 168	At that distance i dont think a 24-26 is needed. Increased velocity? Yes. But that doesnt mean increased accuracy. More velocity doesnt always mean more accuracy, especially at shorter distances. A shorter barrel may actually be more accurate as it does not suffer from as much barrel whip/harmonics as does a longer barrel. A longer barrel doesnt give you more accuracy directly. It gives more velocity in order to keep the bullet supersonic as long as possible and to reduce flight time. But as long as the round stays supersonic at the distance you plan to shoot, a longer barrel may not give any benefit.

February 16, 2015, 10:35 AM	#8
Shooter2675 Senior Member Join Date: August 17, 2013 Location: Western Pennsylvania Posts: 382	Thank you Jimro. 26 inch barrel it is. When I get the funds together and buy the parts I will make a new thread detailing the new build. John __________________ "Better to remain silent and be thought a fool than to speak and to remove all doubt." - Abraham Lincoln

February 16, 2015, 12:22 PM	#9
kraigwy Senior Member Join Date: June 16, 2008 Location: Wyoming Posts: 11,061	Using 223 77 gr sierra bullets: 20 in 2650 fps SS 800 yards 10 mph drift 12.6 moa 24 in 2790 fps SS 850 yards drift 11.6 moa 26 in 2840 fps SS 900 yards drift 13.4 moa SS being the point where the round becomes sub sonic Drift is the MOA drift of a 10 MPH FV wind at the point the round becomes SS Depending on how are you intend on shooting, I don't really see that much of an advantage of anything over 20 inches for an 223. __________________ Kraig Stuart CPT USAR Ret USAMU Sniper School Distinguished Rifle Badge 1071

February 16, 2015, 12:45 PM	#10
Shooter2675 Senior Member Join Date: August 17, 2013 Location: Western Pennsylvania Posts: 382	Like I said mostly matches and coyote hunting. I have several very long guns (26+ inch barrel) and I don't mind the length. To me 190 FPS is a good amount. John __________________ "Better to remain silent and be thought a fool than to speak and to remove all doubt." - Abraham Lincoln

February 16, 2015, 12:47 PM	#11
Jimro Senior Member Join Date: October 18, 2006 Posts: 7,097	kraigwy, If you can get 2840 fps with a 75gr AMax bullet the SS transition doesn't happen until 1,000 yards. Unfortunately the 223 just hasn't ever come into its own as a 1k cartridge. But since the OP is only worried about scoped shooting, the extra mass of the longer barrel (and longer torque moment because of muzzle mass) means less movement under recoil and faster back on target times. Things which have nothing at all to do with ballistics or accuracy. Jimro __________________ Machine guns are awesome until you have to carry one.

February 16, 2015, 12:58 PM	#12
Shooter2675 Senior Member Join Date: August 17, 2013 Location: Western Pennsylvania Posts: 382	Yeah that's one of the reasons I like the 26 inch. Less recoil (it already has very little, and I don't want less recoil because I think there is too much) for faster follow up shots. If I am hunting with a shooting stick as I often do, the weight doesn't bother me and the faster follow up shot might help with that yote that tries to run. John __________________ "Better to remain silent and be thought a fool than to speak and to remove all doubt." - Abraham Lincoln

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