I just picked up an apparent LE trade in 1999 mfg Colt 6520 "government carbine".
I have a couple quick questions.

The carbine has one of the neutered "half circle" BCGs. If I wanted to, could I run a full auto carrier with this lower without issue?


I know Colt made some if their lowers to be incompatible with the full auto carriers but I'm not totally clear which are or are not gtg, as I understand there were a couple variations of these "sear block" lowers.

Secondly, if I can use a FA carrier in this carbine and decide to do so, can I take the existing bolt and put it into the FA BCG and use it in the carbine without any potential for headspace issues or could changing the carrier affect the headspace, even with the original bolt in place?