Last year I posted a thread about a Kimber 8400 that I re-chambered to 300 WSM, and have now had a bit of time behind the rifle. It started life as a 338 WM and feeds the 300 WSM rounds very well. Same image as I posted earlier, but just to put a rifle to the 'story' (Brux light palma).
I initially had it chambered for 185 Juggernauts but could not find a single box around here and picked up some 200.20x. The 200.20x works very well with the 185 throat. The bearing surface/boat tail is sitting just above the 'doughnut' area. Turned the necks to have .003 clearance(overall). Here is a loaded round.
Here are a few of the 200.20x loads that I fired with S365 (similar to H4350). This is where I decided that I will stick with the 200s.
Went out with a buddy of mine that shoots a 7RM and fired 3 shots just after him at 1150 yards. He hit slightly high as we thought it was colder than it actually was (well, that is what we thought). I adjusted a little for the 'error' with a light L to R wind. I was really impressed with the vertical. Bullet velocity 3050 fps.
I am pretty happy with how the rifle performed up till now. The barrel is finished at 30" that makes it tricky to handle at times but the way it shoots and velocity I get, I might just leave it as is. It also seems like the 200.20x performs well on game (not meat friendly with big wound channels). Did not take pictures of wound channels but should be able to do by the end of this month.