This was my first bath of reloading with the 50 BMG and it went well. I basically used the South African 690gr FMJ, COAL 5.45"
225gr= 2389,2428,2398,2405,2395 ft/sec
230gr= 2525,2515,2501, 2510,2518 ft/sec
There were some flattening of the primers but no other pressure signs, all brass extracted and feeding was very reliable.
I also chrono'd factory Barrtt rounds and they came to :
2541, 2552,2572, 2549, 2562 ft/sec
So at 230gr i am slightly slower than the factory Barrett ammo. I think next i will try a batch with 237 gr that will most likely duplicate factory rounds.
The problems I had with "PULLED" WC860 was a 150 to 236 FPS difference in velocity. Using 221 gr of WC860 (PULLED) behind a 657 gr API surplus bullet in CBC brass I got an AV of 2641 FPS with an Extreme spread of 236 and SD of 87.02. (NOT GOOD) I found there was a lot of dust in the powder and used a fan to winnow the dust out of it. I was not happy with it and instead of shooting up the rest of the WC860 I ran into 24 lbs of AA8700 which gave me much more consistency. Out of a 30" barrel I used 218 gr AA8700 w/ ES of 22.87 and SD of 11. Much better with a velocity of 2623 FPS. No signs of excess pressure. I did have some friends shooting a Vulcan with some factory LC ammo w/235 gr of a ball powder and the primers were flattened and cratered. Not performance I' was happy with.