I have a bushmater lower and am thinking of buying a CMMG Gas Piston Upper 16’. Checking the forum to see if anyone has bought a CMMG Piston Upper and what they think.
Final goal is to have a good M4 Carbine for Carbine classes.
Thanks.
If the goal is to just have a reliable M4 type carbine… and you are not dead set on a gas piston upper. A buddy of mine purchased a BCM 14.5 upper and welded an FSC556 on the end of it. I have the same setup but with Bushy parts. VERY nice shooter. Just looked it up on Bravo Company: Just under $700 with everything. BCG, Charge handle, hand guards, and FSC556. Amazing shooter, 0 muzzle rise with that comp. Just a thought.
The CMMG is definitely a good buy for the money!
CMMG makes a pretty good piston setup but it has “issues” under stress.
Point in case: Gent used a RRA M4 with the CMMG piston kit for a carbine class and had lots of trouble after firing only half of his first string. Short stroking and FTF’s.
This was while using xm193 55 gr ball ammo.
YMMV
If he had the early CMMG pistom upgrade I can understand why he had trouble. Lots of issues with the first gen piston kit, don’t buy it. Stick with the Adams Arms kit, much more reliable and easy to install.
It costs more but make sure the piston kit comes WITH the bolt carrier and not just the replacement for your gas key. Run it hard in a good class and there is a chance of that part shearing off. I know of an Adams arms piece that did in a magpul class.
I love my complete piston upper from CMMG,
I think you’d be much better off getting a DI upper from Daniel Defense, Bravo Co., Noveske, LMT, Saber, etc.
The majority of piston uppers I’ve seen tend to have fleas over the long haul, and introduce an entirely new set up issues.
If you’re running a piston then save your money (a lot) do your research, then look at Adam Arms, or LWRCi.
Any other route is kind of tossing a coin and hoping for the best.
On the other hand…
The Stag Model 8, and S&W M&P-15 PSX rifles are very much worth the money.
Honestly the best AR-15s on the market are LWRCi or KAC. They tie equally for me, it all depends on user preference of system. They’ll both stand up to hard abuse.
You don’t actually need a piston. (I would rather have one and not need it then need it and not have one though.)
My direct gas CMMG’s have more than adequate reliability - one gas block was canted out of the box, but once that’s resolved, they’ve only choked on steel cased ammo.
Templar’s advice is what I’d agree with - get a high end DI upper, find a trigger you’re comfortable with, then spend money on quality magazines.
User and magazines are the source of most malfunctions. I really only consider pistons for SBR and/or Suppressed - but as it is I’m still going with DI SBR host weapons.
BCM, DD, Colt, LMT, Noveske, Sabre, and the VTAC line from S&W. Comparable cost, more options.
Look closely, the stag piston and cmmg piston rifles are the same…
Yeah, but I’ve never heard of or seen a Stag rifle malfunction.
On the other hand I’ve seen in person a CMMG operation rod bend.
go with the stag 