I'm considering converting my Beretta CX4 9mm to an SBR and using suppressed. Couple of questions, though. First, since it is basically all plastic, where would I put the engraving? Second, I'm not sure about 992r compliance. Does this seem right for identification of the various parts?
Frames, receivers, receiver castings, forgings, or stampings - 1
Barrels - 1
Barrel extensions - none
Mounting blocks (trunions) - Not sure if the barrel bushing counts?
Muzzle attachments - none
Bolts - 1
Bolt carriers - none
Operating rods - none
Gas pistons - none
Trigger housings - 1
Triggers - 1 but already replaced with Sierra Papa trigger
Hammers - 1 but already replaced with Sierra Papa hammer
Sears - integral with trigger housing
Disconnectors - not sure, probably.
Buttstocks - 1
Pistol grips - integral with Buttstock
Forearms, handguards - 1
Magazine bodies - Use US made
Followers - Use US made
Floorplates - Use US made

Assuming I have a complete US made magazine, that's 8 parts. Does this seem correct? I haven't found anything in my searches for what other's have done.

The maker engraving doesn’t have to be on metal like the serial number. It’s fine on the plastic of the receiver.

To second that I've had to engrave lots of plastic guns like the CZ scorpion. I don't have a CX4 but does it have a permanent pic rail attached, because a really good place to engrave is on that just below the rail itself. and that's metal. On 922r I have no idea without an actual gun to look at but with 8 parts it should be pretty easy.