You are correct. Some are and some aren't.

Perhaps we'll do a comprehensive article on the matter soon, but in the meantime simply come on into the shop and we'll explain all the do's/don'ts and particulars.

BTW, we sell these all day long. They're fun, reliable, highly accurate, and available in all sorts of calibers too from .223 (5.56mm) to 50 cal.

One of my personal favs is the .450 Bushmaster caliber. You can build one of those here too, the upper receiver itself must come from Bushmaster and they're a bit pricey, but if this cartridge takes off we'll be seeing more manufacturers shipping uppers in this caliber.

Post edited by: tallship, at: 2008/07/25 13:16