Cast boolits in my CMMG Banshee?

[bcr]

I've got a CMMG Banshee in 10mm and wanting to start loading for it. I've got a bunch of MP 170 gr. WFN solids that I powder coated, but just realized tonight that due to my OCD I stand them all on their bases and so the bases aren't coated.

Is this going to cause problems with the Banshee? I'm new to the whole AR platform and not really sure about the ins and outs of cast boolits in these guns.

[Kosh75287]

Is the Banshee blow-back operated, or gas-auto? If it's blow-back, I'd expect no issue. If it is gas-auto, there's SOME likelihood that the polymer coat could strip off at the gas port and clog it. But to be honest, I don't hear of it happening very often. Whether it's because it just doesn't happen, or because most shooters are smart enough to not send PC'd projectiles through gas-autoloaders, I have no idea.

[mehavey]

I've had no problems w/ gas-ported actions (ARs or Garand-types) as long as the trailing edge is GC'd.
Even plain base functioned fine/no port fouling -- `just not as accurate because there was some trailing edge stress when passing the port.

[bcr]

Thanks guys! Kosh, it's a radial delayed-blowback, something they apparently developed to handle some of these pistol cartridges.

[Baltimoreed]

As long as the pc is between the lead and the barrel you’re good. I have 2 45acp uppers built with cmmg rotary bolt bcgs/barrels [a pistol and a rifle] and have found that ammo that would run in my Olympic blow backs would be problematic in the cmmg’s. They need round nose bullets. With the correct shaped ammo they run fine. I did have to enlarge my ejection port on a dpms upper but I replaced it with a Midway Stoner upper that solved the problem.