Anyone put a MR556 upper on a regular AR lower? Im also curious whether a regular upper works on the MR556 lower?
Thanks,
Nate
Posted: 5/15/2011 5:33:19 PM EDT
[#1]
Yes and yes.
Posted: 5/16/2011 4:27:30 AM EDT
[#2]
Make note that HK MR556A1 upper requires high hammer (not notched one or short like in Geiselle) to work with firing pin safety. Or you need to deactivate firing pin safety.
