Is this pretty much standard now? I bought a Sabre 16" upper and the pin is shrouded, so I'm curious.

GL

dunno... various makers/dealers do different things.

[Martha] it is a good thing[/Martha]

Any one have more info? What is the reason for the shrouded pin, or why is the pin sometimes not shrouded?

GL

Should ask, "Why were the unshrouded pins introduced?"

At the request of the the ATF, Colt removed the metal under the firing pin and modified the hammer. These mods were to prevent conversion of the semi-auto commercials rifles to full auto or, through the failure or intentional removal of the disconnecter, prevent slam fires.

If for some reason the disconnector should fail to hold the hammer until the trigger is released, the semi-auto hammer will ride up the back of the carrier. With the unshrouded firing pin, the notch in the top of the semi-auto hammer will engage the large flange forward of the firing pin head, forcing the firing pin backwards and preventing a slam fire.