Expedient Homemade Firearms: The Machine Pistol - .2004 by P. A. Luty

In this volume of Expedient Homemade Firearms i will endeavour to show how a
more compact and lightweight machine pistol can be constructed from readily
available off-the-shelf materials.
In these days of anti-gun laws, when firearms may have to be hidden away, the
more compact and concealable a weapon is the better.
The expedient machine pistol is a .32/.380 calibre weapon. The true expedient
firearm is built from the position that no outside influences such as machine tools or
professional gunsmith’s materials are available. For this reason nearly all major
component parts of the weapon, receivers, barrel, breech block and magazine, are
constructed from readily available steel tubing, eliminating any need for a lathe. The
barrel, for example, is assembled from a length of seamless hydraulic tube
reinforced with a series of steel collars and is smooth-bore rather than rifled. While
the accuracy available from the smooth-bore barrel is restricted to relatively close
ranges, the relative ease and speed of assembling the expedient barrel more than
compensates for this necessary compromise.
Manufacturing a gun magazine using the conventional methods of folding sheet
steel around a form block can be tricky and a time-consuming process. The
expedient magazine avoids these problems, as once again it is constructed of tube
and only requires a hacksaw, file, and silver solder to assemble it. The magazine is
of a single stack design holding 16 rounds. This is less than the capacity of the
commercially produced twin stack design, but again, the relative simplicity of
manufacture more than compensates for the reduced capacity.
Certain parts of the machine pistol, such as the sear, require the use of hardened
steel. For this reason, I have incorporated certain off-the-shelf products into the gun
design that are as close to the correct steel types requires as possible. This
eliminates the acquisition and heat treatment of specialised steels which can pose a
problem.
I have not included any sights on the machine pistol as they would only be for
cosmetic purposes, rather than to make the gun more accurate.
The machine gun is primarily a point and fire weapon. Reliability and simple
functionality are the main priorities, especially for a weapon that should be kept as
simple as possible. In short, I have included only what is necessary to ensure the
gun will function as reliably as can be expected.
It should be noted that the life expectancy of any firearm built using the type of
materials and techniques illustrated in this book will be less than that of one built
from the correct steels and to machine tool tolerances. However, due to the ease
with which parts,(such as the breech block and barrel) can be made; it is possible to
keep the firearm in permanent working order by having a selection of spare parts
available and ready for use. A spare breech block and barrel should be regarded as
a necessity.