Longer barrel, accurate - 6mm ARC upper

[CZ527 Guy]

Considering a  upper to add 6mm ARC for a Rock river arms lower. I am vey Happy with a 22" barrel on a CZ527 bolt action rifle. Erroring on the side of longer barrel, school me on selecting a upper for an AR?

Thanks!

[SBRSarge]

I built one on an 18” Odin barrel. It is sub moa all day long at 100 and 200 yards.

If you already have a 22” arc, maybe something shorter would be good. I have a 12” 6arc that I’m still working on, but it is a 1.25 moa gun right now, so it is well under minute-of-deer.

[CZ527 Guy]

You may be on to something that maybe a shorter barrel than my 22" bolt action could be a plus. Though I come from the school of thought that a longer barrel is much like or as as close to a free lunch as you get. So while I am sure I do not want or need a 30" barrel, I'm fairly sure I do not wish to go less than 20" either.

Feel free to make your case either way!

[Old Bob]

If you're just looking for an upper, I'd suggest one from BCM. They're a tight one so it would need thermal fitting of the barrel extension. Precision Firearms has a billet upper I'd suggest as well. It would require the thermal fit also. Precision Firearms has some quality barrels too made to your specs. There's a lengthy wait time though...

[Stonegables]

My first 6mm ARC is built around a Sanders Armory 20" upper. I have only shot 6 boxes of ammo so far. All five shot groups sub MOA except for shooter error.

[CZ527 Guy]

My first 6mm ARC is built around a Sanders Armory 20" upper. I have only shot 6 boxes of ammo so far. All five shot groups sub MOA except for shooter error.

Looking quite interesting to me.  if one is liking the 20" barrel - why not 24" for another 110 FPS or so?

Thank you!

[Stonegables]

My first 6mm ARC is built around a Sanders Armory 20" upper. I have only shot 6 boxes of ammo so far. All five shot groups sub MOA except for shooter error.

Looking quite interesting to me.  if one is liking the 20" barrel - why not 24" for another 110 FPS or so?

Thank you!

I have three AR style rifles with 20" bbls. A DD5V5 in 6.5 Creedmoor that DD says will shoot 1000M accurately, A 25-45 Sharps, and the above referenced 6mm ARC. They all have somewhat heavy bbls. and are at the upper limit for weight and portability for me, a 71 year old curmudgeon with a metal and polymer right shoulder. I think if I was going longer than 20", I would just go for a bolt action or single shot.

[alwie]

Considering a  upper to add 6mm ARC for a Rock river arms lower. I am vey Happy with a 22" barrel on a CZ527 bolt action rifle. Erroring on the side of longer barrel, school me on selecting a upper for an AR?

Thanks!

I am picking about the upper and lower matching well …. esthetically. So, I usually buy matching (Same manufacturer) receivers.  As far as barrel length goes, I would work backwards, but keep in mind that an AR is not a bolt rifle.  For what purpose do you want to use the AR?  What are the high and low distances are you planning on shooting.  What MV  range do you need?  Once you have determined your requirements, decide what feature of the components you what to optimize on(cost, reliability, weight, accuracy, esthetics …) Then strive to optimize while selecting components consistent with your requirements. Next you are ready to build your own upper exactly the way you want it.

I like Aeroprecision receiver sets as they are good quality for a good price.

[CZ527 Guy]

Think Stonegables just may have brought to light the obvious answer. I really do like the longer than 20" barrel. Then when I think about my purpose for an AR & I simply do not have a good answer after thinking on this for a good long while.

So why not just stick with my 22" Barrel on the CZ 527 bolt action & call it a day. No need to add another caliber to the RRA lower. The CZ 527 drop in barrel came in at a better price point & it is what I really wanted in the end. Time to be happy with what I already have, & already know I like.