The lost ‘Arm Gun’
Hank Strange visits with the Matt Gwinn-designed “Arm Pistol” an oddball produced by Bushmaster back in the 1980s for an Air Force contract that never got off the ground in the above video.
What was the Arm Pistol?
Well, it started off in the 1960’s with Dale Davis of USAF Armament Laboratory as the Individual Multi-purpose Weapon (GUU-4/P) and was contracted to Colt in 1968 as a 1.5-pound gun with a 13-inch total length, capable of firing out to 100 meters effectively to be used as a aircrew survival weapon. At the time, SAC bomber crews had .38 revolvers and various AR5 rifles (in .22) under their seats, and could use some more firepower if down in Siberia somewhere. The gun, chambered in .221 Fireball (5.56x36mm), became the IMP-221 Individual Multi-purpose Weapon but never really was adopted.
There were several variants of the Arm Pistol that popped up from the mid-1970s until Bushmaster ended the line in 1988 but the basic concept was a .223 Rem chambered handgun with an 11.75-inch barrel and STANAG magwell but using an AK-47 style piston system. It was the same concept as the IMP-221, but a good bit heavier (2.85 lbs with a full 20-round mag) and a skosh longer (20.63-inches over the flash suppressor).
Offered to the military for use as a lightweight and compact survival piece for aircrew lost behind the lines, the company reportedly closed a deal in 1985 with the USAF for 2,100 guns which was later rescinded, leaving Bushmaster to sell them commercially.
From the Bushmaster Armpistol Manual:
The Bushmaster weapons system was based on the function and operating principles of the patented IMP aircrew survival weapon designed at the United States Air Force Armament Laboratory at Eglin Air Force Base. Subsequent design changes integrated the battle proven characteristics of the U. S. military M16 and the unexcelled gas system of the Russian military AK-47; thus attaining the simplicity and functionability of the current Bushmaster production.
By consistently and methodically applying these principles, it has been possible to make a high percentage of all individual parts in the various weapons comprising the Bushmaster system identical and thus interchangeable both among our various models and with the Colt M16.
The overall concept of the U. S. M16 and Soviet AK-47 have been in military use for many years and both countries continue to produce these proven designs in large quantities. Along with these concepts, the utilization of all practicable new developments in the field of weapons technology, improved materials and the empl.bymenVs of the most advanced machine tools and special equipment insures that the shooter has at his disposal a weapon of .. sophisticated design and technology.
The weapon was so iconic to Bushmaster’s early line, that the company’s logo for years contained the arm pistol outline:
Hank’s is provided by Walter Keller at Safety Harbor Firearms, who has an early model variant with the charging handle on the top of the receiver. Later models used a side-mounted handle.


