New barrel for target upper

[hkmp5ks]

I'm building a precision-focused upper for my competition AR-15 and plan to order a Craddock-Bartlein 5r 400MOD 8.47-7.7 twist barrel... target crown.

Couple questions... I'm split between 20", 22" and even 24"

Will be shooting 69-77gr out to 800ish, occasionally 1000yds but mostly 600ish.

Mostly want something that is very accurate but can reach the distance when needed and has to be .223 for compatibility with my other components and reloading tools/components.

My concern with the longer barrels is that they might be more susceptible to the effects of gravity and force vibrations.

20" seems too close to the 18” I already have and wouldn't mind exploring 22 or even 24" options... what do you all think?

What's your favorite barrel length for a target rifle? I'm not worried about weight. Also, this barrel is going into a VLTOR MUR-1 "beefed up" upper receiver.

I just don’t have any experience with longer barrels in gas guns so any help is greatly appreciated!

 

[Molon]

My concern with the longer barrels is that they might be more susceptible to the effects of gravity

I'm not sure what that is supposed to mean, but the 10-shot group pictured below was fired from an AR-15 with a 24" barrel. The group has an extreme spread of 0.467 MOA.

....

 

[FuhQ]

The shorter the barrel, the less susceptible to harmonic issues. Shorter = more rigid.

I went from a 24" to a 20" in my 6.5 Grendel DMR, and I've never been happier with that rifle. Not only does it shoot better, but it's significantly lighter, and more maneuverable, especially with a can on the end.

 

[hkmp5ks]

I'm not sure what that is supposed to mean, but the 10-shot group pictured below was fired from an AR-15 with a 24" barrel. The group has an extreme spread of 0.467 MOA.

....

Have heard Jeff Siewert talk about the effects of gravity on barrels, albeit much longer ones than anything I'm contemplating. Maybe force vibrations might be more of an issue? Either way I think it's splitting fractions of a hair, so to speak, lol. I'm basically looking for any reasons why I should pick one length over the others, in short...

 

[MTRecon]

I went with a 26" WOA 1/8 twist and actually wanted a bit longer. Would probably go with 24" if the longer lengths weren't available.

I shoot mostly 600 to 700 but sometimes out to 1,000.

Using 75gr RMR with Tac at 556 power level seated at 2.250". Great performance.

 

[hkmp5ks]

I went with a 26" WOA 1/8 twist and actually wanted a bit longer. Would probably go with 24" if the longer lengths weren't available.

I shoot mostly 600 to 700 but sometimes out to 1,000.

Using 75gr RMR with Tac at 556 power level seated at 2.250". Great performance.

How do you like those RMR bullets? Have you compared them to Sierra’s or Hornady?

 

[MTRecon]

The 69s and 75s work great in all 3 of my ARs.

The RMRs work better for me than the SMKs do. Haven't tried any of the Hornady yet.

 

[bfoosh006]

FWIW... here is an older barrel cutdown test that shows some fps differences from a 26 cut down by inches, to a 16.5"

https://rifleshooter.com/2014/04/22...gth-a-man-his-chop-box-and-his-friends-rifle/

 

[Bobby Ball]

Promise not to derail this, but that hornady podcast with Jeff Siewart was absolutely spectacular. One of the best things I have seen in a long time.
That being said I have a 24" heavy Krieger on my 308, and there are times I feel like I am fighting harmonics more than I'm gaining accuracy or speed. I think if it were 556/223 it would be a different issue, BUT, that's just what I think. In my mind the extra action movement of everything behind it is playing a role in that and I have found that an adjustable buffer and gas block had been very helpful in smoothing that. For the current setup I have id be very curious to see what 22" would do, but if I were shooting the current setup in 556 I'd not hesitate to use 24" . I think if I were staying long I'd just want to ensure that I felt like the contour was heavy enough to overcome harmonic/ barrel sag issues to realize the potential accuracy gain of the length. Please update your results I'll keep an eye on this thread.

 

[roostercogburn98]

I run an 18 and 22 inch bartlein in 223, one bolt and one semi. The 600 and in shooting I have done with them seem close to the same for me. The 600 yard dope with 77 grain IMI razorcore is .8 mils difference between the two.

 

[camocorvette]

Have a 20" wilson SS that hammers 3/4" moa too 500 haven't shot it past that with good ammo.

If your moving around I'd go 20". If you don't care about length get the free velocity of a longer heavy barrel.

 

[LiveFire]

Go 22 or 24. I just went from an 18" to a 22" in a 6x45 ar set up. The velocity gain was worth the barrel length.

 

[hkmp5ks]

You guys are gonna be like WTF but this is what I ordered today after talking to Paul Craddock:

.223 Wylde Bartlein Barrel
Brand: Bartlein Barrel
Twist: 8.47-7.7T
400MODBB: Yes (+$250)
Gas Block Diameter: .875" / Medium-Heavy
Barrel Length: 20" Rifle
Thread Size: 3/4x24
Time and Blended Muzzle Brake: No
Thread Protector: Yes (+$20)
Fluting: None
Accessories: Superlative Arms Adjustable Gas Block w/ Tube (+$122)
Headspaced Bolt: No
Finish: Polish,
Built Upper Options: None

 

[LiveFire]

Thatll do what you want im sure. Sounds like itll be a nice set.

 

[Bobby Ball]

No judgement there. That sounds on point.

 

[Old Man with Gun]

I have RRA uppers in 18", 20" and 24". The 18 is thinner barrel profile than other 2, but all shoot 1/2" to 3/4" consistently. 20 is the best mix of ballance and velocity. Don't over think it, other than a slight velocity bump they will shoot the same.

 

[hkmp5ks]

Well I'm looking forward to it! Thank you all so much for your help!!

 

[Merle]

Why the 3/4-24 threads on the muzzle?

 

[hkmp5ks]

Why the 3/4-24 threads on the muzzle?

Two main reasons, the muzzle device I plan to use is threaded for it and I also like the idea of having more meat at the muzzle for when I run a Sandman L, which is a heavier 7.62 can that I sometimes run on these gas guns

 

[MTRecon]

I noticed WOA is threading their varmint barrels with 5/8x24...probably the added mass as well I'm guessing.

 

[Old Man with Gun]

I noticed WOA is threading their varmint barrels with 5/8x24...probably the added mass as well I'm guessing.

Some believe the extra diameter keeps the crown area from "swelling" so better accuracy. Maybe, but I've gotten such good results with 1/2-28 it would not factor into my barrel selection.