what caliber of case would we have if we blow a 50 bmg case out straight. jason

It would have nothing to headspace on.

Monte R. Kyser did a three part experiment into wildcating the BMG case. The articles can be found in the FCSA magazine Very High Power (VHP) 2000-2, 2000-3, 2000-4 issues. His creations range from the 375 KTB 3.3" (210gr BarnesX @ 4000fps, NOTE- State Arms in WI makes a Mach-5, a .375/50BMG which shoots over 5000fps) to the 700 KTB (1,925gr Advance Design VLD bullet). The 700 has a small shoulder to headspace on. I would think this is the largest you could go.

I made a dummy round of what I call the 75 acp. I scaled up the 45 acp, and it worked out to a .750" bullet, don't recall the case length, I believe 1.3". I turned a bullet out of Aluminum and seated crudely via a vise.

The brass is difficult to work due to the thick walls, if you wanted a shoulder to work with, the practicle limit would be .70", so a rimless 700 NE, or I guess one could call it a 700 Nyati? Considering the price of 700 NE brass, a 700 Nyati would be relatively practicle.

I like the blunt nosed 900 gr 600 bullet better than the rather pointy 700 bullets, which are harder to come by anyhow. Sounds like a ripe opportunity for a 600 Super (900 gr at 2500 fps+). For the guy who thinks the 505 Gibbs and 500 Jeffery are on the light side. That would work out to roughly 12,500 ft-lbs of muzzle energy.

Just don't expect me to shoot it!