Good info, much appreciated. There is just something about putting 50 BMG rounds in an over that feels... interesting, hehe. I did read that some FCSA shooters will keep them in a container @ around 115F, single feeding of course to keep the temp stable.
Looking over my previous data: LC brass, 219g of H50 was pushing CE 762g MTAC’s at 2601 FPS. Relatively "short" 27-inch barrel on the McMillan TAC-50. A tad faster on the AW50 @ 2619 FPS. Will probably have a 34" barrel spun up for this rifle. Never really got around to testing temp stability back then.
I will definitely run the VV 20N29, but I think I’ll try some RL50 in order to make a comparison and see what the "new" rifle likes.