Professional Ordnance carbon fiber AR-15's were junk and, due to a bunch of proprietary parts, they were incompatible with most standard AR-15 parts/accessories. When Bushmaster took them over years ago they went through the gun completely and changed everything to standard (mil-spec) dimensions and also made them reliable. The Bushmaster guns are good shooters, I used a C15-M4 as my patrol rifle for several years.
Your brother wants too much money (especially since you're his brother) for what he has. Bud's Gun Shop has brand new flat top Carbon 15s with a red dot for $699 right now.
“Never give in. Never give in. Never, never, never, never—in nothing, great or small, large or petty—never give in, except to convictions of honour and good sense. Never yield to force. Never yield to the apparently overwhelming might of the enemy.”
Last edited by WC145; January 1, 2012 at 12:29 PM.