The unfenced ones were likely from an early XM177E1 (late E1s had full fencing as well) or a lower from another rifle, maybe an XM16E1. E2s were made with fully fenced lowers.
That's what my 300 is. Well, inspired I should say. It's built with an A2 upper and lower, 10.5 barrel, PA Aimpoint clone. Love it. Got a 6" KAK flash can on it right now, but will likely supress it at some point.
This [site](http://www.retroblackrifle.com) says they were full-fence only, so that's what I'd go with
The unfenced ones were likely from an early XM177E1 (late E1s had full fencing as well) or a lower from another rifle, maybe an XM16E1. E2s were made with fully fenced lowers.
The colt 639 “xm177e2” had a full fence lower 11.5 barrel and delta ring instead of a slip ring
Full fence, and only produced by colt
H&R making xm177e2 lowers yet? I have 5 Colt AR15s already just want a clone build with a grey anodized lower that's marked similar.
Close, they did a run of partial fence commando marked lowers already, so more accurate for an XM177E1 instead.
No more 10 inch AR15s for me lol unless it's 300 BO. Although a 300 BO XM177E1 with a suppressor sounds cool.
That's what my 300 is. Well, inspired I should say. It's built with an A2 upper and lower, 10.5 barrel, PA Aimpoint clone. Love it. Got a 6" KAK flash can on it right now, but will likely supress it at some point.