Skinny,
I bought a heavy barrel varminter, a RR, and while being a tack driver, it was just to heavy to carry around, 16 1/2 lbs. without ammo. I picked up anothe flat top upper, lite weight RR, took the frount sight off and put on a 3 x 9 Leupold. Ideal carry gun for coyote hunting with dogs or for any carry situation. I bought some of the cheapest 55 gn. bullets I could find and, not knowing what I had, I loaded 5 rounds with a mid range charge. I took them out and shot a .700 group at 100 yrds. Not a bench gun group, but this ammo is for coyotes when shots will be off hand and usually at running targets, so I never went any farther with load development.
This is the only AR I have ever owned, but I do know afew guy that are really into them and the consences of oppenion seem to be you can beat RR, but Bushmaster and DPMS are both righ there trying.
My lower had a super trigger for a hunting AR so I did not want to let it go. I would let the heavy upper go, but not cheap as it would make a great PD rig. If your happy with your lower just get another upper. If not just get another gun. Do alittle looking, there are some AR that look more like varmint rifles than military gun.
and shoot like them too.