Ron458 - What are the brands/models of each of the bullets shown in the picture you just posted? Are those standard 458 Socom cases?
For spitzer bullets I'd agree on the 50 AE giiving better load densities than the 50 Beowulf, but using the 600 grain RBT shown above seated to standard 50 Beowulf OAL the load density just right for subsoinic use. The long shank and short ogvie engages the rifling with little jump. The rebated boattail is mostly to use up case capacity and add weight rather than giving higher BCs. It's not a partularly low drag desing though it's mass makes the BC higher than other bullets which will feed though an AR-15 magazine. Yes, it could be used with a 50 AE case in a custom chamber but not in a SAAMI spec 50AE chamber. It was designed specifically for the 50 Beowulf standard chamber and 16" (length and twist) barrel for use in magazine fed AR-15s. I wouln't consider it for a subsonic bolt action. For that i'd use the cartridge next to the far right below. It's 582 gn with a subsonic G1 BC greater tnan 1.0 and will feed nicely from a Rem 700 LA magazine. Its case capacity is close to the larger diameter but shorter 458 Socom next to it. For that you could probably rebarrel a Browning or a Cobb MCR to shoot it if a semi-auto is more desirable. Perhaps even an M1 Garand.
The cartridges left to right are 223 rem, 458 Socom with 280 gn Lehigh flat base, 338/7mmBR with 245 gn Lehigh boattail, 308 Win, 458 Socom with 582 gn Lehigh boattail, 458x2 American with 582 gn Lehigh boattial, and a 7mmStW. The end and middle cartridges are just for size comparison..
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