[QUOTE=Zundfolge;1405581]The grip frame of the Sig P250 is NOT a registered part, that's the point of using the P250 as a base. The whole point of the P250 is that you buy one "Fire Control Group" which is the serial numbered "Firearm" according to ATF and then swap out grip frames and uppers to your heart's content. Here's SIG's page which explains it much better.

This is the FCG ... the "Firearm" according to the ATF.




Neat, did not know that.