I've never owned either of these brands of AR, so am looking for feedback & opinions on one vs. the other for an upcoming build.

I'm considering the CMMG 55B3CDE vs the Rock River AR550 uppers for a rifle I'm putting together. Main superficial differences is that the RRA is 20" with 1:8 twist & the CMMG is 18" with 1:9. For 'reaching out there' the 20' barrel with faster twist is slightly more attractive for bullet-weight & velocity reasons, but having no experience with either of these brands, I'm curious for info, opinions, and any feedback on the relative overall quality of one vs the other.

Any info would be appreciated; thanks.

I'd go with the RRA. They have a great reputation for accuracy and I'd prefer the 1:8 twist for that kind of gun. And FYI, either of those is going to be a heavy mother so just be aware of that.....

Could you let us know what your definition of .... "reach out there" is?



What optics will you be using? What is your skill level? What type of shooting environment are you building this for?



Thanks,



Hobo

"Out there" being as far as reasonably possible; part of the reason I'm leaning toward the 20" 1:8 is to maximize the gun's capability in my hands with appropriate bullets. I do some medium-range shooting - rarely over 300 yards and almost never over 400 - but not much of it and not real often; and it's with bolt action, not semiauto. I've been shooting AR's for over 30 years, but they've almost all been carbines; nothing set up with accuracy-at-range as a main consideration.

This is intended to be my critter gun on the farm - coyotes, fox, gone-feral dogs, etc. On optics, I haven't decided on a specific model yet, but odds are it'll end up being a medium-end leupold varifocal. I just can't hardly bring myself to buy anything but leupold for centerfire guns anymore.

Basically, all my other AR's are defensive in nature, and I just want one set up less for defensive/LE use, and set up more for farm & hunting use.

I think you'll find those bull barrels are just way too heavy for what you have in mind. I have a 20" RRA built on the middle barrel you see pictured here and even it is a bit much to be carrying around very long.  

Depending on how soon you want this and what's in stock at the moment, you might talk to these guys about putting something together with a barrel like this, just as one example: https://www.rainierarms.com/?page=shop/detail&product_id=3324.

Or something like this - nice setup, good price, should be very accurate: http://www.rockriverarms.com/index.cfm?fuseaction=category.display&category_id=569

Lots of good choices out there, I just wouldn't go with one of those bull barrels unless you've been able to hold one in person first.

The RRA will likely be the more accurate upper.

For the intended farm pest control use you describe, a 1:9 twist might be better, as you are likely to be using lighter bullets.

I don't see the need for the longer, heavier barrel.  I have a CMMG 16" M4LE  1:9 WASP (hot salt bath nitride) barrel on my AR build.  It is spooky accurate with bullets in the 55-62 grain range shooting 1 MOA or less.

I'm not sure a longer, heavier, bull barrel is going to be much better for the ranges you plan to shoot.

Assuming the OP is not going to hang a bunch of stuff from the handguard, he can mitigate the heavy barrel with a Clark Custom carbon fiber FF tube.

I've been using them for years.  They're good to go.

http://www.clarkcustomguns.com/clk750.htm

I use this barrel for the distances the OP described.  16" SPR profile 1/8 twist Wylde chamber
http://ar15performance.com/inc/sdetail/11562/4307

reviews here of both brands has been good.  I don't own either but have rarely read anything bad on either.

bravo company has 20 inch barreld uppers in stock 1/7 twist and goverment profile

Thanks for the replies. How about another perspective on the question:

If you were looking for a new upper for use as I described, and had the choice of just these two. With the minor cost difference (RRA = $130 higher), which would be your choice. The price difference is almost a non-issue, as it would be well worth it to have the more expensive option as long as it were the more capable one.

So #1: if the choice were only between these two, for use out to 400-500 yards which would you be more likely to go with?

And #2: is there typically a real difference in overall quality between the two brands?

#1: RRA
#2: I have both brands, though not those exact uppers, and I'd say there's no observable difference in quality but RRA has the better reputation when it comes to accuracy.

if those were the only two choices I would go with rock river . they have pretty accurate barrels