[xraykat]

interested in purchasing an olympic AR 15 i will also looking at the bushmaster who i was told were made by S and W any advice THANKS

[Spktyr]

Um, no. Bushmaster receivers are not made by S&W.

Most AR-15 lowers are built by one of four companies, though there are plenty of other companies that make their own, and of course you can churn one out in a CNC machine shop in a few hours.

Here’s an FAQ on the major receiver makers, how to identify them, and who makes what:

http://www.ak47.net/forums/topic.html?b=3&f=12&t=318113&page=1