Hi There,
You might be a little surprise, but I don't recall ever measuring the groups :oops: I know that the first ammo I loaded for this rifle and used for sighting in and hunting was using the Sierra pro Hunter 180 Grn bullet (rifle is a .308). Let a friends buddy try it out at the range and he banged them all in the bull from the prone postirion and complained that the recoil was a bit much. It was then John told me that Phil his mate had only just started shooting rifles :roll:
I switched to using the Speer 165 grn flat based bullet after the Suerra bullet blew up on te first deer I shot with this rifle (my first Deer) it was a Roe Doe which only weighed about 35 lbs and the bullet blew up on her ribs at about 90 yards, clipped a rib going in and blew out three on exit, she dropped on the spot however I didn't think a 180 Grn bullet should come apart on such a light animal. Shot the rest of the ammo loaded with those Sierra's at the range. Never had a problem with the Speer bullets. Recently I tried loading some 125 grn bullets, I use them in a custom 30-30 bolt action rifle so I thought I would try them in the CZ. So far the accuracy has not been what I am looking for as I am getting about 2-3" groups. Need to try a different powder and test it again, time is the enemy here. Those 125's shoot wonderfully in the 30-30 at about 2800 fps so I cannot see why they would not shoot well in the CZ, just have to find the correct powder and charge I suppose.
Meanwhile the ZKK 601 has taken a fair few Deer, Roe and Muntjac and as Muntjac only stand about 18" at the shoulder the accuracy has never been a problem.