WHAT'S THIS PART?
Take a close look, while you may know it already, it may require some research to be sure.  Photo  or photos are best we could take.  Scale is provided to aid you, either with a rules or small coin.  In your email please identify the firearm and purpose of item, ie.  barrel cam lock nut for the Browning Model 1919 series machineguns.

Unk center fire firing pin
Unk center fire firing pin

No Price

Rim fire? extractor
Rim fire? extractor

No Price

Some kind of a pawl or round pusher?
Some kind of a pawl or round pusher?

No Price

Retainer or catch plate
Retainer or catch plate

No Price

Front sight guard, LMG?
Front sight guard, LMG?

No Price

Round MG bolt
Round MG bolt

No Price

Flat machine gun bolt
Flat machine gun bolt

No Price

Have fun and show off your knowledge.