Obviously for ARs it's the lower, but what about the ACR? Is it the upper? Is there somewhere official that has this information?
If Bushmaster ever ends up selling upper receivers separately, you could have two uppers; a restricted and a non-restricted, that could be swapped if you wanted to shoot in the woods or at a range.
If Bushmaster ever ends up selling upper receivers separately, you could have two uppers; a restricted and a non-restricted, that could be swapped if you wanted to shoot in the woods or at a range.


















































