I have 2 so far. One I built into a 444 Marlin for deer hunting and do about a 1.5-2" grouping at 150yds with it. I just use a bipod mounted far forward on the stock. Works like a champ. The other is one I am playing with. I built my own "chassis" stock for it and for now am playing with a cut down sporter barrel in 243 Win. I have brakes I built on both of them and recoil is about the same as a 357 in the 444 and like a 38spl in the 243.

I would be doing some practice and playing with different support positions. Also check your scope and all the mounts, see if they are loose anywhere. You could just be having a scope moving around on you or a scope that won't hold adjustment.