Wildcat Cartridges for Handguns
There are still some gaps to fill!
43Auto / 11mm Auto
A .44-caliber cartridge for common semi auto pistols
At the first glance it is astonishing that there are only few wildcats for
handguns. But it is much easier and cheaper to buy and install a barrel in a
rifle action -whether new or reworked- than building a pistol barrel and make it
function flawlessly. And a new cylinder for a revolver is anything but easy to
manufacture.
This leaves room for more or less new designs.
A neglected calibre for semi automatic pistols is .44 (.429 bullet dia.) which
is so popular in revolvers.
An early famous attempt to build a 44-caliber self loading pistol and cartridge
was the 44 Auto Mag(num Pistol) in the early 70’s. Though it helped to make
Dirty Harries day it didn’t really survive. Maybe it was too much gun and
cartridge to be attractive outside a special interest group. That could be
dramatically changed when you are focused on Colt 1911 size handguns and if the
new cartridge has a significant advantage over the venerable ones.
The 43 Auto is intended for 45 ACP semi auto pistols. It is based on a shortened
44 Special, 44 S&W Russian or 44 Magnum case with the rim and extractor groove
turned down to 45 ACP dimensions. As the rim is slightly larger than the base it
is in fact a semi rimmed design but it headspaces at the case mouth. A new
barrel and a new main spring are mandatory and could be enough for switching to
this calibre. An unknown factor is feeding this type of case out of a 45 ACP
magazine in a particular pistol model.
According to QuickLOAD this cartridge offers the same performance as the 10mm
Auto but at considerably lower working pressure:
Barrel Length:
5”/127mm
Bullet Weight:
200grs
Total Inside Volume of Case:
25.5 grs of water
Maximum Working Pressure:
26.100psi / 1800bar
Muzzle Velocity:
1200fps / 365m/s
These QuickLOAD data seem to be plausible because a .429 dia bullet has a lower
sectional density than a .400 dia bullet of the same weight. Lower sectional
density means better acceleration inside a barrel –and higher drag outside.
The 11mm Auto is identical in performance if powder space volume is equal. Its
rim diameter will be a problem for most pistols designed for 45 ACP. The bolt
face of the slide must be adapted. Additionally or alternatively the operating
angle of the extractor must be increased. Cases for the 11mm Auto can be built
without a lath but a special die set including a reamer for removing inside
material can not be substituted while the 43 Auto simply uses dies for its
parent case and a 45 ACP shell holder.
48 Auto
The ‘475 Wildey Magnum Short’ = 380 Auto on Steroids
A 475 caliber handgun cartridge is still exotic. In 2014 someone in a Colt 1911
forum had the idea of shortening the 475 Wildey Magnum to a case length of 0.9
inch for using it in a 45ACP pistol. The
48 Auto
is nearly identical to this proposal. Wildey Magnum cases are currently
available from Starline and shortening would be an easy operation. In a 45ACP
pistol with a high capacity magazine “only” a new barrel is necessary. Frames
built for single row magazines will be a challenge for passionate pistol smiths.
Asking QuickLOAD one gets these predicted values:
Barrel Length:
5”/127mm
Bullet Weight:
240grs
Total Inside Volume of Case:
30.6 grs of water
Maximum Working Pressure:
23.200psi / 1600bar
Muzzle Velocity:
1170fps / 356m/s
Barrel Length:
5”/127mm
Bullet Weight:
280grs
Total Inside Volume of Case:
30.6 grs of water
Maximum Working Pressure:
23.200psi / 1600bar
Muzzle Velocity:
1080fps / 329m/s
Recoil of a 48 Auto pistol of that performance would be more than enough for
most shooters.
It is still possible to find information about the 475LeHigh. It follows the
same design philosophy as the 48 Auto but is based on the 480 Ruger case.
