PDA

View Full Version : Rainier Arms "Combat Series" Upper/CMMG Lower Build



Bizzarolibe
07-21-12, 21:23
Ok, so this rifle just hopped off the workbench an hour ago. I really, really like the upper. The lower, well, not so much. I bought a CMMG blem lower and PSA lower build kit. The PSA kit is great; no problems there (except they forgot to include the MOE trigger guard and put a standard one in instead--I'll give them a call about it Monday to get it straightened out).

But the lower, well, it won't drop PMAGs. Or USGI mags. In fact, you have to put quite a bit of force to get either kind of mag into the magwell. I'm really disappointed and will contacting CMMG about it, but I doubt they will do anything to help me out since I've already built on the lower.

In any case, here are the components (in more standard fashion):

Rainier Arms CE16 upper w/ Samson Evolution rail system
CMMG stripped lower
PSA Magpul STR lower build kit
Magpul RVG
Magpul MBUS (front and rear)
Viking Tactics 2-point sling
Streamlight TLR-1

To be honest, I'm also not sure if I like the STR stock. It's alot heavier than the CTR, which is what I've had on all my rifles up until now. The only reason I got the STR kit was because it was only a few dollars more than the CTR kit and I was curious. I can't say for sure that I don't like it though; I'll give it a few range sessions before I make up my mind.

The upper I chose because it's just a sick upper. It's got all the desireable specs, and comes with RA's XTC muzzle device, a Daniel Defense CHF barrel, and is of course a mid-length. I also love the rail system, as it is very lightweight and has a nice slim profile.

For this rifle I decided to try out the 12:00 light position. It doesn't obstruct my sight picture (for right now I'm just running irons; I've got optics on my other rifle and am content with irons for the moment) and is very easy to actuate, so I think I'm going to like it. It does look kind of goofy though, I'll have to admit.

http://i40.photobucket.com/albums/e236/Snarky15/AR5.jpg

UPDATE: so I went ahead and took a file to my lower. It actually works fantastic now. I also got a chance to shoot this thing and man does it shoot. With irons--and as ashamed as I am to admit it, I've never shot with exclusively iron sights before--I achieved a 4" 10-shot group at 100 yards using sandbags and PMC X-Tac M855. I think I will be posting a full review in the GD section later tonight.

strambo
07-22-12, 08:53
Nice build. Sorry about the lower, my CMMG lower works great w/ GI and Pmags, I even SBR'd it. I hope CMMG makes it right for you.

Quentin
07-23-12, 00:05
Nice build and I hope CMMG can help out with the lower.

I know what you mean about the STR, I have two very similar carbines, one with CTR and the other with STR. Have swapped back and forth and still slow to warm up to the STR even though it only weighs 3.5 oz more. I do like the extra cheekweld though.

fallenromeo
07-23-12, 11:21
how well does the STR lock up? I don't have any experience with them personally, but a friend of mine said it doesn't feel as solid as his old CTR did.

Tzook
07-23-12, 17:40
how well does the STR lock up? I don't have any experience with them personally, but a friend of mine said it doesn't feel as solid as his old CTR did.

I haven't had a CTR before, but the STR I have on my Noveske locks up super tight, and I actually really enjoy it. I was planning on replacing it with a B5 or LMT SOPMOD, but I think I'm gonna hang on to it.

Merle
07-31-12, 21:34
I have one of CMMG's "milled lowers" that costs twice as much as their forged lowers and it wont drop P-Mags either but is fine with everything else. I bet that after a while with some prolonged use and maybe a little lube in the mag well it will loosen up a bit, but I guess that depends on how tight it actually is. I don't really mind on mine because I don't really use P-Mags anyways.

Tzook
08-01-12, 11:52
I have one of CMMG's "milled lowers" that costs twice as much as their forged lowers and it wont drop P-Mags either but is fine with everything else. I bet that after a while with some prolonged use and maybe a little lube in the mag well it will loosen up a bit, but I guess that depends on how tight it actually is. I don't really mind on mine because I don't really use P-Mags anyways.

You might be able to sand your PMags just a touch and get them to drop free if you can figure out the spot(s) that's making them stick

yallknowho
08-04-12, 12:26
You might be able to sand your PMags just a touch and get them to drop free if you can figure out the spot(s) that's making them stick

that's not really an adequate fix

Merle
08-04-12, 12:31
that's not really an adequate fix
An adequate fix is just to not use them. Cmmg isn't the only lower that has a problem with pmags not dropping free.

yallknowho
08-04-12, 12:46
I'd want my lowers to work with all mags. you never know what you might have to use in a pinch.

Merle
08-04-12, 13:10
I'd want my lowers to work with all mags. you never know what you might have to use in a pinch.
Pmags work they just won't drop free. I guess if you found yourself in a pinch you'd just have to pull it out.

yallknowho
08-04-12, 15:23
Pmags work they just won't drop free. I guess if you found yourself in a pinch you'd just have to pull it out.

:laugh::laugh:

rhegar4
08-04-12, 18:03
OP -Are you saying that Rainier uses DD CHF barrels for all their uppers or just this one? Or is this a special order?

friendlyfireisnt
08-04-12, 18:40
OP -Are you saying that Rainier uses DD CHF barrels for all their uppers or just this one? Or is this a special order?

Rainier has stated previously that they are using DD barrels for these uppers as well as their RUC carbines. They have also said that they may have other suppliers for barrels as time goes on, but that at that time, they were using DD barrels.

MrSmitty
08-09-12, 10:59
I tried out the STR for a couple months on a 10.5" and it made the rifle feel very bulky and heavy. I moved back to the CTR and it was a world of difference. For me, the STR may be a better fit on a precision rig. This is all personal preference though, YMMV.

Mine locked up just as tight as my CTRs on an A5 extension.

FourLoko
08-10-12, 22:39
loving that upper, it's on my list, probably in a LW profile since I already have a couple beefy ones

if it happens it will be my first free floated and comped rifle

Bizzarolibe
08-12-12, 20:34
You might be able to sand your PMags just a touch and get them to drop free if you can figure out the spot(s) that's making them stick

Yeah, that wouldn't really have been an option since I have other AR's that will be using those magazines. Since I filed down a few parts of the magwell, everything actually works very well now.

I got a chance to shoot 120 rounds at the range a few days ago and it shot flawlessly (again). I'm really considering getting a 1-4x scope for this thing...I think it would make a phenomenal semi-precision/CQB rig. I've always used Aimpoints and Eotechs, but I may just have to branch out in this case. If I got a 1-4x, it would probably be the Vortex Viper PST.

Oh, and I've decided that I do not like the stock. Anyone wanna trade?

Frag Out Inc
08-12-12, 21:28
This is one of the nicest AR builds I have came across this year! Even booked marked it to share on Facebook! I also would be worried about the mag not dropping out freely but I have watched videos of trainers having trouble with this in high end guns so cmmg is not the problem. You run your rifle enough your going to come across every malfunction...eventually!