CMMG Radial Delayed 9 mm - First trips

[tekmann2377]

I have always wanted a 9 mm upper or 9 mm subgun for range plinking. I was never the biggest fan of straight blowback uppers for multiple reasons, most namely they are loud, and they tend to have a higher recoil impulse than locked breech systems. I also didn't want to deal with a mag well adapter or dedicated lower.

Anyways Midway had a sale on CMMG radial delayed uppers several months ago, and I picked up a 5" complete Banshee upper. I finally got around to shooting it.

In short, it runs great. Digested 115 and 147 hr loads without issue. The CMMG magazine that goes in a standard AR magwell worked without a hitch, and the BHO worked too. It suppressed reasonably well with a Primal 46.

I used it on a standard AR lower with a Geiselle SD3G trigger and standard carbine buffer. There were no trigger issues either.

I didn't shoot it enough to conclusively establish it's reliability but so far it has been off to a solid start.

 

[mattc51]

New fixed ejector or old style spring ejector on the bolt? Reliability will be effected if it is the old spring ejector.

 

[Sheldon N]

I've always been interested in getting one of these as a fun range toy.

Have you followed the articles/recommendations for upgrading the buffer setup to smooth out the recoil impulse? The go-to recipe seems to be an A5 length buffer tube, a Tubb flat wire 308 spring, and a Kynshot RB5007 hydraulic buffer.

 

[tekmann2377]

To be honest I don't know what kind of ejector it is. The ejection pattern is 4 o'clock and very brisk, and there did not appear to be any issues with weak or inconsistent ejection between different ammo either.

I am not bothering to do anything with the buffer, spring, or buffer tube. This pistol lower is shared with a 12.5" 5.56 upper as well and I don't want to induce any reliability issues with that. I don't shoot subgun or pistol enough to bother with optimizing the setup if it runs fine.

 

[mattc51]

Keep track of round count. The spring ejector AR bolt style have a life span of about 300-500 rounds before ejection goes down the toilet. The spring tunnel for the ejector will be full of gunk and the spring will be too short to eject the shell. They will send an extra strong spring and it will do the same after the same round count.