Long story short I've been shooting 178 ELD M for a couple years. Had a load worked out. Switched to Lapua brass(it's a 308 by the way) and redid load work up. Groups went to crap. Went from half MOA to 1.5 to 2. Redid load workup with once fired brass and still crap. No other changes. FGMM still shoots half MOA. Only other thing is I opened a new box of bullets. Any ideas?