I was looking to get a new AR. Actually was going to order a Colt 6721 with a heavy barrel. Got persuaded to get a long piston design Mk116 rifle made by PWS (Precision Weapons System) at a favorite gunshop. Handled one and it was also broken down so I could examine the parts. Weighs a little under 7lbs. All makes of two stage triggers are supposed to fit. I won't get mine for 3-4 months so won't know how it will shoot until then. Seems to be a lot of favorable reviews on it.