Is that a hole, or a bunch of holes in one spot? Mallard, I'm not calling you an A-hole. Pretty darn spot on in any case.
Its A-hole. lol Ammo's is too expensive to shoot more than 1 to check the big boomers these days.
Although.......... I had a guest at my house, and we burned the crap out of his 300 WSM barrel trying to get those Speer 165 grain and Hornady 165 grains to shoot. Best I could get him was 1" groups at 100 yards. He was looking for more but with the components he had, we had to stop somewhere. Groups were from 1" to 3". I as frustrated. We loaded and shot from 7:00AM - 6:00 PM. Ended up shooting 75 rounds in total. We spaced the shots in the 3-shot strings 3 minutes apart shooting 3-shot groups to see what was working. 3-shot strings were 10 minutes apart to let the barrel cool. The barrel on that gun is super thin.
I never used 4350 and I have never used CCI magnum primers. Thats the only thing I can think was causing the issues. Winchester Model 70 all-weather stainless rifle and with the factory 165 federal ammo he brought it printed a SUPER tight 3 shot group at 100 yards. Literally 1 ragged hole......so that told me that we didn't have a loose base/rings/ damaged scope ect ect.
Also, the throat/freebore on that rifle was freaking deep. I pinched the brass and tried to find the lands and I'll be honest, the lands started way down the bore.....so far that the bullet was protruding so far out of the case that I just backed everything up to published SAAMI COAL and called it a day to have something consistent. My intentions were to stay about .015 -.020 off the lands but there just was no way to do it. I checked this SEVERAL times because at first, I thought that I was pulling the bullet when I was ejecting things. I checked it 5 times and came up with the same results. Too freaking long....
Finally, we settled on the Speer 165 bullets and 66 grains of 4350. Its 1" groups and I guess maybe that's all I can/will ever figure out for him because he was already starting to get antsy about the cost of everything, we had burned though....
I have never had this many problems with loading for a gun to find something that would shoot. Wish he had brought some 150 and some 180 pills to try out of it. Oh well. 1" groups are good for a factory rifle. If I was him, I would be trying to find a few boxes of those federal fusion 165's that it shot so well......