Re: 416 Barrett vs. 375/408 SOE
The BMG cases will go past 50,000 some fella's are loading them up too 65,000# That is max for any case due to brass becomes semi liquid at 70,000# The 50 spotter round is loaded with a 835gr projectile at 2350fps mil specs. That is moving for the large bullet and small case, there has to be some high chamber pressures there. The big thing is with the 50 cal case you get the larger case head and heavy webbing. The Action is larger and can take more thrust. Re-sizing the full size 50BMG case can be real fun if you run the loads hot, takes a hell of a press to handle that squeeze. I dont plan on loading mine over 55,000 for starters, but who knows where it will top out at. But so far this project is on the drawing table, test results are the only way to see how efficient the case is going to be.
Kirby is working on a 50cal in the chey-tac case, wont know the speeds until he shoots it, my guess is a 750amax around 2300fps. And yes the cases will take a beating.
Short bbl guns usually loose around 300fps over the standard length, that is why the long range pistol shooters can do so good with the same chamberings, 18-20" bbl lengths that is. I ran the numbers on the Snipe-Tac with a 20" bbl, it was right at the 300fps loss range. A 300grn MK pushing 3000fps out of a 20" bbl Would make a neat mountain rifle.