Wildcat idea: 500 S&W case + .510 barrel + 50 BMG bullets

C

Crosshair

New member
I can't have been the first person to think of this for a 510 Whisper type of cartridge, so someone tell me if this has already been done so I can just copy them.

Take a 500 S&W case and seat a 50 BMG bullet into it. Bam, 30-40-ish grains of powder capacity. Whisper territory.

Of course the 500 S&W uses a 0.500" bore, so you would need a custom 0.510" barrel with a longer throat to allow those longer bullets. Not sure how to specify the throat or what a good value would be.

I was thinking about using the Bauska BBK-02 Magnum action I have for this. I made up a dummy cartridge and with the BMG bullet it will feed from the magazine. The rim is slightly smaller, 0.556" for the 500 vs 0.588" for the 338 Lapua. A difference of 0.032", but the extractor seems to grip it just fine.

So, lets see what everyone else thinks about this.
 
Would the case be long enough to handle that large a bullet and still leave you with any powder room?

I think most .50 projectiles for the BMG are about 2 inches long. Even with minimum seating that would only leave an inch or a bit more for powder...

I think you'd be really hard pressed to make this work, but it is quite intriguing.

I know the .510 Whisper uses .338 Lapua cases that have been cut back to just shy of 2 inches... But, it has to be necked to seat the bullet, which means you get a bit more powder capacity.
 
I've read that the .500 case doesn't work well from stack magazines, something about the rim getting locked up with the extractor.
 
Underwood makes ammo for the 500 S&W with 700 gr. bullets at 1200 fps.
I believe Ranger Rick offers 700 gr. bullets.
They are flat nose so I don't know how well they will feed in different actions.

Jim
 
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"Underwood makes ammo for the 500 S&W with 700 gr. bullets at 1200 fps."

Those are basically flying thermoses. The bullets have very little taper. Because of that, they're significantly shorter than a .50 BMG bullet.
 
Since rimmed cases are problematic when used in magazine why not use a rimless case like the 500 Auto Max

or better yet just get a AR500 and load subsonic

be safe
Ruggy
 
Many rimmed cartridges have been used in magazine-fed semi-automatics over the years.

Rimlock is a fairly rare happening and every case I've ever seen has been the result of a damaged magazine or operator error in loading the magazine.
 
Many rimmed cartridges have been used in magazine-fed semi-automatics over the years
Click to expand...

Yep
Including my fave the 54r. Dragunov, PSL, SV-98 and the modern Vepr- all mag fed. Most collectors also are familiar with the SVT-40 autoloader.
 
Not just rifles, either...

Colt & Smith & Wesson .38 Special target semi-autos.

LAR Grizzly .357 Magnum.

Desert Eagle .357, .41, and .44 magnums

Dozens, if not hundreds, of different .22 LR chambered semi-autos.

And let's not forget the British Bren gun, one of the most successful and effective light machine guns of all time.
 
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