.500 HWP Magnum

Do anyone know the history of the .500 HWP Magnum? Case length is 35,5 mm (1.4 inches) and it is very much like the .500 Linebaugh. In The Blue Book on Gun Values (24th Ed., pg. 713) it says that a HWP Industries made a stainless steel 5-shot “The Sledgehammer” revolver in cal. .500 HWP Magnum in 1989. Is this the same cartridge as the .500 Linebaugh?


Hi Morten,

on the brandt’s book these two cartridges are described as different cartridges, although in the .500 Magnum description is written “on investigation, it was thought that it could be identical to the Linebaugh cartridge”.

Dimensional data show that these two cartridges are almost identical, except for small differences in head/ rim diam and case lenght.

These are the dimensional data published by brandt:

500 Linebaugh

bullet: 0.509 - 0.510"
c. mouth : 13.7 - 13.72 mm
head: 14.02 - 14.04 mm
rim: 14.58 - 14.60 mm
case lenght: 36.61 mm - 36.63 mm

500 magnum:

bullet: 0.511 - 0.513"
c. mouth: 13.78 - 13.82 mm
head: 13.78 - 13.82 mm
rim: 15.07 - 15.12 mm
case lenght: 35.47 - 35.52 mm

Anyway, my .500 Linebaugh sample is closer to .500 magnum Brandt’s dimensional data:

bullet diam: (ouside the case) .509"
mouth diam: 13.70 mm
head diam: 13.76 mm
rim diam: 15.19 mm
case lenght: 35.31 mm

Commercial sample, by Buffalo Bore, lead bullet. This could explain some differences from the wildcat version made from 348 Winchester brass

I remember picking up a draw set of the HWP 500 at Jim Bell’s plant back in the 80’s when we had a school bus trip to Bell Laboratories plant at the Chicago Cartridge show. I can’t quite remember the whole name from the initials, but I think it was H. Wesson Pistol.

I did find a little more about the HWP 500 Magnum.

I have a flier mailed Dec 1988 from the HWP Industries Box 83047 Milwaukee, Wisconsin 53223. Phone at that time was 414-242-6610.
They state that the design of a new cartridge began in November 1986. They also at least produced their pistols in 41 Avenger or 11x22 HWP. The cartridge for this was made from a short necked down 30-06 case.

Yes Gary, the 41 Avenger is nothing more than a necked down version of the 45 ACP case. Similar to the 40 Super or the 400 Cor Bon, but with a longer neck and, obviously a slightly larger bullet

The thing to remember about the .41 Avenger is that J.D. Jones designed the chamber so that it would accept cases formed by necking down either the .45 ACP or the slightly longer .451 Detonics Magnum. As the .41 Avenger headspaced off of its shoulder, the chamber would tolerate the difference in neck-length. Beside the rare factory brass, .451 Detonics Magnum brass could also be formed by cutting-down cases from the .45 Winchester Magnum or even rifle cartridges.

I seem to remember an article on the .500 HWP where the five-shot revolvers were converted Dan Wesson Model 44.