generic answer about ar15's...the commercial semi auto version of the mil m16...a1/a2/a3/a4......
essentially no "manufacturer" make an ar.
they all ASSEMBLE COMPONENTS THEY BUY FROM SUB CONTRACTORS.
THIS APPLIES TO ALL.......( ONE COMPANY IN UTAH ACTUALLY GETS CLOSE)
bbls, buttstocks uppers lowers triggers...you name it....
so there are about a dozen companies that make uppers and lowers, and a whole slew of small companies making the rest of the parts, plus all the after market parts.
the big difference in most of these is the level of inspection to drawing compliance. what they pay for compliance, affects cost, but ensures quality.
there are several companies with years of history with quality...colt, armalite, rock river, stag...bushmaster was once, but moved and has an unknown hostory at this point. there are several johnnie come lately companies with glitzy names and stuff and high prices...your call... silly to me.
( stag is an exception to the process..thier parent company..cmt is a MAJOR maker of ar parts...so thier costs/quality is inhouse ensured...thier rifles reflect both resonable cost and great quality)
there are several 2nd tier companied , in my opinion...i would not own them.....not allowed to post names.
sw probably fits in the upper catagory but is acutally very late getting in to the ar game....
mike in co