I guess I look at it a bit differently than most guys. Personally I could care less what size group a rifle shoots. All I care about is where that first cold bore shot goes. I could care less where the second or third shot goes in an MZ.
Depending on what rifle I am shooting I want my rifle to hit where I aim. On my open sighted MZ's I want the projectile to hit about 1-1/2" to 2" high at 100 yards. And I want that first shot to touch the vertical line of the target. As long as that first shot cold bore bullet cuts that line then I am fully satisfied and ready to go hunting. I do not shot second dirty shots from a barrel at deer-so why do I care where it goes??
Most rifles will hit a bit different with a dirty barrel than it will a clean cold bore shot. Especially an MZ.
I completely clean my barrel between shots when preparing my rifle for hunting.
And when I practice shooting I don't waste my time shooting it off a bench. I take it in the woods, or I go to my rock chunkin spot and I practice in hunting condition environments.
IMO guys put too much emphasis on groups from a bench. I don't hunt from a bench. And I don't shoot groups at deer, I shoot a single shot. So just make sure you know exactly where that first clean cold bore shot is going to hit, then go practice in hunting conditions and I hope you kill a biggun this year. Tom.