The .38/.45 Clerke (pronounced "clark"), aka .38/.45 Auto Pistol or .45/.38 Auto Pistol is a wildcat semi-automatic pistol cartridge developed by Bo Clerke and introduced in Guns & Ammo in 1963.
History and design
It is essentially a .45 ACP case, necked down to .357, resulting in a cartridge similar in form to the earlier 7.65×21mm Parabellum and 7.63×25mm Mauser cartridges. It was created to be a low recoil target cartridge that would function reliably with multiple bullet types, FMJ to cast lead wadcutters without the feeding problems that straight walled pistol rounds sometimes exhibit. The cartridge can be used in standard .45 ACP magazines.
The .38 Casull followed the same formula as the .38/.45 Clerke, but with thicker case walls as in the .45 Winchester Magnum.
Ammunition and reloading
.45 ACP cases can be resized to handload .38/.45 Auto cartridges  using form and sizer dies still available from the RCBS Corporation, p/n 56468.
Nearly any M1911 pistol and pistols of the same pattern can be converted to the .38/.45 cartridge with a replacement barrel, from a 38 Super barrel reamed out to .38/.45 dimensions. During the round's initial popularity, drop-in barrels were available from makers like Bar-Sto.
- ^ a b "none". Guns and Ammo magazine. October 1963.
- ^ Robert K. Campbell, The Shooter's Guide to the 1911: A Guide to the Greatest Pistol of All Time, p. 122, ISBN 1-4402-1434-4
- ^ a b Patrick Sweeney. Gun Digest Big Fat Book of the .45 ACP. pp. 329, 332. ISBN 1-4402-0219-2.
- ^ John Taffin, "Flat-shooting trail gun: Casull 3800", Guns Magazine (February 2003 ed.)
- ^ "1911 Hot Rods", Guns & Ammo- Handguns Magazine, archived from the original on 2009-06-17
- ^ Barnes, Frank C. (2006) . Skinner, Stan, ed. Cartridges of the World (11th ed.). Iola, WI, USA: Gun Digest Books. pp. 140, 143. ISBN 0-89689-297-2.