I worked up a lot of loads with H-414, and Berger 75gr VLD's with Molly.
I started at 35.0(2800) and went up to 44.5(3670FPS) Anything over 44gr was much to hot in my gun.
I settled on a load of 43.5(3532fps) These loads worked great at home here where a VERY HOT day is 85*f, and they averaged right around 1/2 " very consistently.
I connected on a woodchuck at a hair over 725yds the first day I had it out.
My gun is a bench only gun, with a tight neck, very heavy 1/8 Hart barrel with a heavily weighted stock for a total weight of 32#. It has a Premier Reticle 6-20 Leupold.
I trimmed, weighed, and sorted through a lot of R-P brass to get 500 good ones, but they worked out good for me.
When I took the gun out to South Dakota for some PD's, and did some shooting at 90*f and higher it all fell apart.
The bullets all became a gray cloud at 50 to 75 yards out, and never reached the dogs. I actually found a jacket on the ground that a small trap door opened on the side of the jacket where it rode the rifling, and ALL the lead was out of the bullet.
I called Berger, and was told to keep the speed down closer to 3000 fps if I was going to hunt in the higher outside temps.
I just worked up a new load with the Berger's (I tried the Hornady 75's but they won't work at all in my gun, fliers, and even keyholes, but they may be fine in your
The new load is 36.5 of H414 and they average 3117fps with 1/2 " groups.
I'm leaving for S.D. a week from tomorrow, so in a few weeks I'll know how they work out.
While doing some testing with 60gr Sierras and 31gr of IMR4064 @ 3050fps (used for fire forming) I got some really nice .150 to .261 groups !