I didn't use H-4895, but I have used IMR 4895, so the burn rate is almost identical. The data is on this thread, back there somewhere. I started w/36 grs, ended up w/ 40. The best result was right in the middle @ 37.5. Vel was 1337 fps. (300 gr. bullet) w a SD of27.3
To be honest, I had better luck w/ 4198. As to the difference between the bullet weights, I have noticed very little difference w/ anything between 300gr and 350. If you do use H- 4895, I'd start out w/ the 33 gr start up. I think Ken Waters tried that years ago. he settled w/ 4198.