mauserand9mm's last sentence is the answer IMO. When shooting my light 404 Mauser from the bench I also found it hurt a little sometimes, even with cast bullet loads. It was always due to having the rifle sitting too low on a sand bag on the bench and the butt pushing more to the top of the shoulder rather than into the meaty part of the upper chest and shoulder. I now use a bipod (yes heaven forbid) but this makes me sit upright at the bench and roll with the recoil.
I do clamp my hand around the bipod and forend junction to stop bounce as you get when using bipods and heavy recoiling rifles. I don't use a bipod for hunting.

I am able to pull off some very good shots for testing the grouping abilities of the various loads I try and the POI is the same as shooting offhand.