Whatever you do just start low, work up and look for psi. If you seat slowly it will minimize case swelling and eliminate problems being pushed back out too.
I had problems using 250gr X bullets in my 338WM for that same reason. The bullets are long and when seating them on top of 72gr of IMR 4350 they would bulge the case if not seated VERY slowly and in little steps downward.
Powder was crunching from almost the beginning of the stroke. If I seated them in one stroke they wouldn't even come close to chambering because of the swelling just below the shoulder.
The powder would also push the bullet back out immediatly around .050" if not done very slowly too.
The Ruger would shoot them into less than a 1/2" hole but I knew pressure was on the high side with them going 3050 FPS on average using Federals HE brass.
Primer pockets lossened up after about 4 reloads, and when the brass was gone I already had my Ruger 416wby and stopped playing with it and sold it.
IMR4831 would get the same velocity but with only 70gr, I never played around with it beyond about twenty rounds though.
Bolt lift was always smooth but primers were flattened pretty good. No ejector groove marks were ever visible but primer pockets verified only after 3 reloads the psi was high, 10% of cases were pitched and wouldn't hold primers snugly to load a fourth time and after the fourth over 50% were unusable.
Normal Remington or Federal brass only yeilded about 2800 FPS with the same loads, so all I ever used was the 60 factory fired High Energy brass I had.
For some reason accuracy was just astonishing with these HIGHLY compressed loads.