Anybody have a Bushmaster Varminter HB 24" stainless upper that could verify if this is a factory assembled Bushmaster upper? I received my upper in the mail today and after inspecting it, I'm wondering if this is a factory assembled Bushamster. The only stampings on the barrel are M1S SS, no indication of the barrel twist or manufacturer, nothing just M1S SS. Upper receiver is a A3 keyhole upper with aluminum free float handguard, no bolt/carrier or charging handle. Would I be assuming correctly that this stamping is for Model One Sales and not Bushmaster? Does Bushmaster use barrels with this stamping on their factory assembled uppers? Wondering if the seller did a switcharoo on me and never said a word about not being able to supply the upper that I ordered? Thanks in advance. I would have posted this in the Bushmaster Forum but it seems after reading some threads there, Bushmaster is a little busy at the moment. Go figure. I'm happy that I finally received my upper. However, if this isn't a factory Bushmaster upper, it's going back to the seller on his dime. I wanted a Bushmaster upper for a reason since the lower I bought was a Bushmaster.