First time out with my massaged .375 Weatherby; was reworked by Jim Brockman.
I fired some fire-forming rounds of 235gr Speer cheapo slugs over 78 grains IMR-4350 using CCI-250 primers. I was much surprised to see the 10-shot group about 6 inches in diameter. They used to not hit the target, and my targets are pieces of cardboard box (about 18"x24"), with a Magic-Marker dot in the center.
After some adjustment I popped off a couple rounds of 300gr. Barnes TSX over 76 grains H414 for 2536fps average. More adjustments to the Meopta 2x8 ranging scope and had three bullet-holes touching, and about 1" high.
I had three rounds of GS Custom 265 grainers over 88gr. of some powder, which I need to find that little green book; had two holes touching and one flyer. Velocities here were 2886, 2895, and last (the flyer), 2869. Hhmmmm. Need to make some more of these.
Long and short of it: I like this rifle now. It began as a plain ZKK-602 imported from a fellow in Kamloops B.C. Had it re-chambered to .375 W, only to find out three months later that Weatherby was reintroducing the round. So much for exclusivity.
Brockman found the receiver was twisted 0.065", plus a couple of other minor things, the result being the rifle would ony "group" rounds. He machined a set of Talley base-blanks to fit, cut a new crown, removed the barrel recoil lug, and now this thing is great!
My loads on the 300 grain TSX are really low-end, and can be bought up almost 200fps if I care to do that. I might try later on this winter, and play with seating depth, as these bullets were seated to just touch the lands. But as it stands, I am entirely confident I can take headshots out to 175 yards. Did you hear that Marvin?
I also need to reinstall the pressure gage I had on the barrel as I want to map the progress of the pressure, using different bullets. I have some nice Sierra 300 grain spitzer boatails I'd like to use to test the ranging reticle of this scope.
Ya, I know this thread is worthless without pics, I still have the target, so I'll get it out of the boat and post it in an hour or so.