RigPig
Well-Known Fanatic
Ok, ok, let's get this thread turned back around to the topic at hand, JBO Spartan lowers. I assembled my lower yesterday, with no problems. I really like that there's no roll pins involved. The bolt catch is pinned to the lower with a threaded pin, and of course there isn't a trigger guard roll pin to contend with. The rear takedown pin retainer boss is also threaded and a plug is included to retain the spring and detent in the event you want to remove the buffer tube. There is also a set screw under the grip location for tensioning the upper receiver for a tight fit. I am using a Vltor MUR 1S in this build, and the receivers fit together as if they were a matched pair, with that set screw backed out, so I didn't use it.



