A 200 gr Hornady PSP with 53.0 gr IMR 3031 will give me 3/4" groups at 100 yards. I haven't ever checked the velocity, but it's under max by a couple of grains. It grouped so much better than the faster loads I just stuck with it. In my .357 the Rem 200 PSP groups about as good as the Hornady's and they are cheaper.
Hi Paul...It is seldom, actually very seldom, that a particular load performs well in one rifle, and then again just as good in totally different rifle.
It seems that 53.0gr IMR 3031 behind that 200gr Horn PSP does just that.
I am seating my bullets 1/2 die turn off the lands and use a "press-on" crimp by removing the stem of the sizer die, and running the loaded round very lightly back in the die. My Whelen is not a NEF either, and do I have to wonder if this load would work as well in a NEF.
I tend to think there is something else going on that is causing the problem with the "Rocky Mountain" rifle...I just can't contribute that much difference to the ammo, or "tool marks".
I also own a NEF, in 45-70, and I KNOW that where I rest the hand guard on the shooting rest has a LOT to do with where the POI is. I have "floated" the barrel, and added that magic bushing over the screw attachment...all to no avail. If I don't sit the "swivel" on the bag, it is going to hit somewhere else, especially if the barrel touches the bag. But, if that swivel is sitting on the rest, and I'm applying pressure with my left hand on the top of the barrel over that swivel, my gun will stack 'em up at 50yds, and right around that 1" mark at 100yds...sometimes just a wee bit less.
I would suggest the CT Kid take a look at the forearm, if there is a shinny "spot" on the wood, sand it off until it is no longer touching the barrel. I use "Belgium Blue" on the barrel, and keep sanding until it no longer leaves a mark on the wood....certainly worth a try.
Respectfully, Russ