Use accuracy loads from Nosler reloading manual. 1 1/4" @ 200 with both out of custom .243 winchester 1x10 twist. H4895 is around 4000 fps and Varget load is around3600 fps. Varget load is similar to 22-250 velocity with 55 grain bullet.
Good comfortable load (half grain below the manual maximum because it shoots best there) for the 55g NBT in my Savage .243 is 44.0g of IMR4895, WLR primer, Win Brass, seated 0.020" off the lands. Shoots them into ~1/2" groups at an average 3,855 fps out of a 22" barrel.
I have about all the same to say except I use 45 grains of IMR 4895 and I found better accuracy with the 55 gr. Sierra Blitzkings over the Nosler 55's. Maybe my Tikka likes green tips better than purple tips.