This is what i have found,shooting from the bench: When shooting free recoil,as you have stated,shots are to the right{ I'm right handed}.As to shooting with a slight grip on the fore end,shots go left ! WHY?
IMHO.A few things come into the picture. Shooting free recoil,you cheeck puts little or no pressure.on the stock? This causes you to get a slightly different sight picture,through the scope.When fireing,the gun will react to the bullet coming out the barrel.{freely} The gun will jump up and tourqe to the right or left.{twist built into the barrel} How you pull the trigger has bearing on this also?
Holding the gun,your face is tighter to the stock{Different sight picture,agan?}. Your grip,on the fore end,more or less,calms the right hand tourqe,so it jumps up and straight back{more or less?}.
The fit of the front stock to the sand bags or front rest,also has some effect.also.
Unless you are shooting Bench rest matches,don't worry alot about shooting free recoil!
My guns weigh 11lbs.I shoot these free recoil.They are 22calipers.
I get so use to doing this,when i go to shoot my 308 sporter for hunting season,I get wacked by the stock! So far,the scope has missed my eye brow?



As I've stated,this is MHO.