Mark, there is a huge difference in loads between a 140g Barnes Tripple shock, the 140g Nosler Ballistic tip, and the 140g Nosler/Win Combined Tech bullet.
The C/T bullet does not build pressures anywhere near as fast as other 140's and I have been able to push it faster with out pressure issues.
Large sloppy factory chambers change the ballistics on this cartridge tremendously vs a Min spec chamber with +.0005 over bullet dia throat and minimal freebore.
For your rifle, you will just have to work up a load, stopping when you see pressure issues...you are a very experienced reloader.
I use Win brass since I can no longer get PMC 300 Weatherby brass to make these cases out of.
I also had excellent accuracy and velocity fireforming Rem 300 Weatherby brass with the 140's, but had to throw the brass away after fireforming due to enlarged primer pockets. If I knew how much bigger the Win Mag primer was, I would have kept the Rem brass for another couple of firings.
