Advise For New .223 Upper With 24” Barrel

[Fire4EffectCA]

I have a Colt CR6724 Accurized HBAR Elite AR15 with a 24” heavy stainless steel barrel chambered in 223 that is an absolute joy to shoot. I can easily shoot ½” or less groups with N133 powder and 52gr SMK bullets. 69gr SMK’s group under an inch.

I would like to build an upper that duplicates the results of the Colt CR6724, but with a faster twist for heavier bullets like 77gr SMK’s. I was going to order a 24” Krieger 1-7.7 Varmint Barrel from Compass Lake, but I keep reading that 24” barrels are less accurate than shorter barrels due to harmonics. The weight of a 24” barrel does not bother me since I shoot from a bench. I see Compass Lake offers their Varmint Barrel in the following contours:

.875 (1″ UHG, .875 Gas Block, .865 Muzzle)
.936 ( 1″ UHG, 9.36 Gas Block, .925 Muzzle)

Barrel lengths offered are 18”, 20”, 22”, 24” and 26”.

My local range up in the redwoods only goes out to 100 yards, but I do belong to the Coalinga Rifle Club that has one range that goes to 1,000 yards. I must say the velocity for Winchester 5.56mm 55gr White Box was impressive at 3,445 fps out of the 24” Colt barrel. I only load the 52gr SMK’s to 3100 fps.

My question is should I steer clear of a 24” bull barrel for my new upper and go with something shorter in one of the two contours offered above? I will eventually head down to Coalinga Rifle Club to see how far I can push this new upper.

 

[JS/]

I own one of the 6724s also...very accurate with Hornady 60 gr. Vmax. I would go with a 20 inch SPR contour Krieger or Bartlein. I've been having the same internal debate about the heavier contours, but the AR15 flattop is somewhat weak at the barrel junction. That is why some manufacturers are building the beefed up upper receivers, so I've been calculating prices on building a whole new upper group. Right now the stock rifle with a Magpul PRS and an old Leupold m3 scope brings the weight to a bit over 11 pounds. I don't want mine heavier...I have heavy varmint bolt guns for when I want heavy. Just my thoughts...you gotta do what you want.

 

[Molon]

I keep reading that 24” barrels are less accurate than shorter barrels due to harmonics.

I guess my 24" Krieger barreled AR-15s didn't get that memo.

....

 

[Fire4EffectCA]

I own one of the 6724s also...very accurate with Hornady 60 gr. Vmax. I would go with a 20 inch SPR contour Krieger or Bartlein. I've been having the same internal debate about the heavier contours, but the AR15 flattop is somewhat weak at the barrel junction. That is why some manufacturers are building the beefed up upper receivers, so I've been calculating prices on building a whole new upper group. Right now the stock rifle with a Magpul PRS and an old Leupold m3 scope brings the weight to a bit over 11 pounds. I don't want mine heavier...I have heavy varmint bolt guns for when I want heavy. Just my thoughts...you gotta do what you want.

Thanks, I appreciate the input. I already have all the parts to build the upper except the barrel. I chose a BCM M4 upper.

I see Compass Lake offers a Kreiger 1-7.7 SDM 20” Barrel.

SDM .223/5.56

Bolts that are added to you order will be headspaced to your barrel. Complete Bolt

compasslake.com

And a Kreiger 1-7.7 SPR/Mk12 18.1” barrel. I imagine this could be ordered in 20” length.

Krieger 1-7.7 SPR/MK12 18.1″

Contours: -SPR/MK12 & (.850 UHG, .750 Gas Block, .7495, .725 for Allen Eng. Ops Inc Collar and Brake)

compasslake.com

What is the consensus about fluting like on the Compass Lake SDM barrel above? I have read that accuracy can suffer as a flutted barrel warms up.

Also, I had not planned to thread the barrel for a brake since we must shoot from narrow stalls and the noise from a brake would be too much for my already ringing ears. I guess I could have the barrel threaded with a thread protector and use a brake when I would shoot out in the open at Coalinga if I want to suppress recoil

.

 

[Fire4EffectCA]

My two favorite rifles to shoot both have 24 inch barrels. I can’t remember the last time I have shot any of my AR’s with 16 inch barrels. None of my 18 or 20 inch barrels will match the performance of the 24 inch barrels.

I looked at the AR-15 barrel contours on Kreiger’s site and I am leaning towards something similar to their Varmatch contour. The Compass Lake 1″ UHG, .875” Gas Block, .865” Muzzle contour will fill that bill. I don’t see a reason to go with the .936” gas block. I am still on the fence about SDM fluting under the handguard since I have never had a fluted barrel on any of my rifles, but would like to check it out.

 

[Codiekfx400]

I have always thought 22” might be the sweet spot. I just ordered a WOA varmint 20” the other day. I have a Krieger 24” 7 twist varmint barrel currently that Keystone accuracy did for me. It shoots well but not any better than my 24” woa varmint. If your looking for accuracy I would forget the fluting and the threaded muzzle. If you do thread the muzzle make sure to go 5/8-24. I have heard nothing but good about Compass Lake as long as you go 223 Wylde.

 

[Fire4EffectCA]

I have always thought 22” might be the sweet spot. I just ordered a WOA varmint 20” the other day. I have a Krieger 24” 7 twist varmint barrel currently that Keystone accuracy did for me. It shoots well but not any better than my 24” woa varmint. If your looking for accuracy I would forget the fluting and the threaded muzzle. If you do thread the muzzle make sure to go 5/8-24. I have heard nothing but good about Compass Lake as long as you go 223 Wylde.

Thanks so much for your input. Compass Lake recommended I go with a 5/8-24 too, but it is unlikely I will thread the muzzle. I had considered experimenting with a tuner. Regarding the chamber. Are there issues with the CLE chamber?

 

[Codiekfx400]

I am not a expert on the CLE chamber but here is a thread about it.

Wylde Chamber vs. CLE Chamber

I am looking at a accuracy build and was down to thd decision of choosing a chamber. I am planning to order a 20 inch Krieger barrel from Compass Lake Engineering and can't decide on the chamber. CLE seems to push the CLE, but it seems the Wylde is much more popular. I am wondering if anyone...

www.snipershide.com

 

[Baron85]

I have a 24” lilja barreled AR and it shoots amazing. With 75 Hornady OTM’s, 77 sierras, and 53 vmaxs.

With that said I think 20”s is probably the longest I will go in the future simply because I don’t really use AR’s for long range stuff and a 20” would do everything I want an AR for out to 600 or so yards.

 

[TonyTheTiger]

I have always thought 22” might be the sweet spot.

I have just about every length other than 24". I think 19" is gonna be my next attempt at a sweet spot.

 

[WittyOwl]

I have always thought 22” might be the sweet spot. I just ordered a WOA varmint 20” the other day. I have a Krieger 24” 7 twist varmint barrel currently that Keystone accuracy did for me. It shoots well but not any better than my 24” woa varmint. If your looking for accuracy I would forget the fluting and the threaded muzzle. If you do thread the muzzle make sure to go 5/8-24. I have heard nothing but good about Compass Lake as long as you go 223 Wylde.

I have always thought 22” might be the sweet spot. I just ordered a WOA varmint 20” the other day. I have a Krieger 24” 7 twist varmint barrel currently that Keystone accuracy did for me. It shoots well but not any better than my 24” woa varmint. If your looking for accuracy I would forget the fluting and the threaded muzzle. If you do thread the muzzle make sure to go 5/8-24. I have heard nothing but good about Compass Lake as long as you go 223 Wylde.

I have a ton of 1:7 SS blanks on hand that will finish at 24". Bolt gun or AR.

JS

 

[semperfireloading]

I have both Krieger and Bartlein from CLE. Same twist, same 20". Of those, the Bartlein is slightly more accurate, but this proves little. lol

And also, it is a myth that shorter barrels shoot more accurately. I would argue the opposite, unless its strictly, like 50 yard target or something. You want velocity to buck wind at distance, even 100 yards matters. I typically buy 20" barrels,. WIth very good barrels, they can do sub .5" groups with more than 5 shots. LIke here is a couple targets from 20" barrels, with .750 gas blocks, and these are 7 shot groups. So you have an N140 24.0 doing .4 group, and you have a SW Precision Rifle 23.8 doing a .2 group with 7 shots. But even with top tier barrels, you can see many groups in the .6-.7 range when you take even 7 shots. You can see I commented how accurate each group is with 7 shots, then took best 6, then best 5. So you can see BIG difference between best 5 and all 7. in the .2" group, 6 shots were in the .1 territory.... in my opinion, that was rare day, because its not repeatable over and over. But around .5 is in "some barrels". AR15's commonly do flyers for various reasons...

Oh, also, ZERO issues with CLE chamber. I often take 5-7 20" AR's to range and test same load, back to back to back to back to back. The CLE Chambers shoot within ~20 FPS of every other chamber from other brands