Same thing for me with a switch from LC Match brass to Peterson Palma brass {now just called sm rifle due to copyright}I agree with other post. Potential is there. In my 223 I was using Federal brass, shot decent. Switched to Winchester and it improved very little. Switched to Lapua and it shot the tightest groups I've ever shot with that gun. Same load same everything on the above mentioned and all I changed was brass only .









