u/SlamfiredSKS

Title. Something like the Sig MPX makes sense given that it has a gas piston operating system. Handguns seem to be exempt for the most part being blowback breech operated. My understanding is that direct blowback and delayed blowback do not have direct impingement, gas tubes, pistons, or any sort of gas cycling beyond the barrel pressure putting rearward force on the bullet casing against the bolt face.

I recently picked up an AP5-SD before this mess of a bill goes into effect just in case. Just trying to get some additional context. Thank you and happy 4th!