I' m firstly going to say that it' s probably your ammunition, if the gun is putting the bullets on top of eachother at 50yrds, I' m assuming you mean one snowman?, but you get terrible groups at 100yrds, look very closely at the holes at both ranges, and move out to 125yrds and back to 75yrds, if you can out to 150-175-200yrds, you' ll be able to see bullet tumble if it is, but you may not be able to notice it if you don' t test a couple different ranges, when it' s fully keyholed, I' m pretty sure you' ll notice it. Get some 150grainers, no reason to need 180' s, and certain gun makes (rifling rate) won' t stabilize them properly.

I won' t say it isn' t your flinching, and I won' t say that it isn' t just your rifle, or just your rifling rate, but I' ve had bad experiences with certain guns and 180gr bullets, and I' ve had many more bad experiences with Rem. Core-locts. I' d say first try switching ammunition to at least a lighter bullet, if not a different make, then do the flinch test that several have mentioned above, Man is it funny when someone flinches the dickens off a rifle when they dry-fire one, but at least you find out you have a problem, it' s hard to see a flinch under recoil sometimes.