Heavy upper receiver s Feb 3, 2016 22:54:05 GMT -8 via mobile Quote Select PostDeselect PostLink to PostMemberGive GiftBack to Top Post by gunmutt on Feb 3, 2016 22:54:05 GMT -8 I generally like the side charging heavy duty uppers for my bull barrel builds. Where does everyone gets theirs. The last I purchased was a Fulton armory and it was nice. Pricey but nice