I replaced the factory handguard on my LR-308B on Saturday morning. I had already replaced the gas block with the DPMS SASS low profile version and verified function and zero a couple of months ago. About a 2" group at 200 dead center with 3 round shot in under a minute. Right where it should have been after tossing the QD mount and scope back on. Yesterday afternoon I take the same rifle back with the same ammunition (165 gr Accubonds at 2550 fps) with the only change being the handguard and at 100 with the same scope I am getting 3 or so inch groups from a steady rest. Let it cool down, take it to 200 and I can still hit a metal ram, but groups are getting so big that I wouldn't bother taking it out to 300. This from a rifle that I was easily taking to 500 yards with the same scope. If I hadn't been shooting this thing for 3 years with much better results, I wouldn't be so surprised, but it has always been an MOA or better rifle. I just hated the short handguard. I am taking this thing black bear hunting this week, but shots will be under 100 yards so the degraded accuracy shouldn't be a concern there. I would really like to fix this thing that I messed up since I have over 2k invested for it to shoot 3 MOA. Does anyone have any idea what I did to cause the sudden inconsistency? I checked the tube, it isn't hitting the gas block. I followed the instructions sent with it to the letter. It makes me wish that I would just just thrown the rifle length LR-308 tube on the existing collar and called it a day.