I have two Browning A-bolt rifles, a stainless .338mag with a custom muzzel break, and a regular blued (black)Rem. 280. I load my own, and use premium bullets. My .280 is a sub 1" moa using most 140 gr. bullets, and is just about as good with heaver bullets. However my .338 dosn't like anything above 180 gr.I'm still working on that problem. I usually shoot test groups of 4, then let the barrel cool. I found that removing the bolt and elevating the barrel cools it a lot faster (convection). I also clean it after it has cooled down for the next test group, trying to make "all things equal as possible" for each test group. I had an older model browning 338 that had the fluted bolt, it shot everything perfectly, a serious tack driverthat just enlarged the first shot by a fraction. I sold it and got the .280 due to some shoulder surgery I had, afraid the .338recoil might damage my shoulder, BIG mistake. The new .338 dosn't hold a candle to my first one, however the recoil is about that of a 30-06 with the muzzel break, the only plus I can see so far. Every rifle has it's own personality, you just have to figure out how to get the best out of it. If you can't get it to work, get rid of it and try something else.