I cast for the 50 Beowulf as well. First time I did it I didn’t let the bullets age enough and they swelled in the case. I wound up having to pull 200 rounds of ammo that would not chamber. I was not having a good day at the range that day.
I have been using a Lyman 452651GC 315 gr. bullet sized .452 with 14 gr. of Unique and a CCI400 primer in my Ruger American Ranch rifle. Groups about 1″+ at 50 yds and 2.5-3″ at 100 yds. Not bench rest accuracy but good enough for hunting. In terms of recoil it is very pleasant to shoot.
I have a NOE 454-280 IIRC it was a group buy on CB couple Years back. Nice bullet.
I have been having good results with the Lyman 457122 Gould Express HP. Pushed with 5744 from my bolt Its shooting under 2″. (Mostly under 1.5) This load will not function my AR. But my bolt loves it @ 1600 cast in COWW.