It's A Gas

American Handgunner, May, 2000 by Charles E. Petty

Where the gas gun shines is with hot ammo. I didn't have enough of the hot 165 gr. Cor-Bon loads to do a complete test with them, but the difference was quite remarkable. The front sight barely rose and the pistol was ready for another round. You really could tell a difference between ball, 185 gr. P and then the hotter 165s. I would love to see some testing done with the .45 Super.

While the gun is not offered as such, it would seem to me to be an ideal candidate for .45 Super if it were durable enough. Only some extensive testing can answer that question.

The gas gun can be built for almost any cartridge suitable for use in the Government Model. Adkins has done some work with the 9x23 and is quite fond of the hotrod. It might be fun to try making one in .38 Super. The limiting factor will be the magazine size. Heck, he might even be able to adapt the system to bigger framed 1911s, such as the Coonan or LAR Grizzly, which would open doors to the .45 Win. Mag.

It is great to see someone in a small shop working hard and being innovative. The gas gun works both in theory and in practice, but there are still a couple of questions to answer and finding the happiest combination of magazine springs may be the toughest.

                       "Gas Gun" Accuracy Test Results
Load                           Velocity Group 1 Group 2 Group 3 Average
Federal 185 gr. SWC             774 fps  2.45"   2.70"   1.77"   2.31"
Federal 185 gr. JHP             907 fps  2.04"   1.68"   1.88"   1.87"
Speer Gold Dot  P 200 gr. JHP 1,066 fps  1.63"   1.84"   1.89"   1.78"
Norma  P 200 gr. JHP          1,045 fps  2.60"   2.67"   2.04"   2.44"
Win. Winclean 185 gr. FMJ       834 fps  2.19"   2.18"   2.35"   2.24"
Average                                                          2.13"
Notes: Accuracy results are 10 shot groups at 25
yards from a Ransom Rest. Velocity is the Instrumental
average of 30 shots at 10" as measured by a PACT
Professional chronograph.

Adkins has a sight of his own make that uses brightly colored inserts.

Standard bushing style barrel above, shows how the gas piston would be located when it is installed in the gun. Below, shows them apart.

Below, the gas system is machined from an oversize Douglas barrel. The gas tube is threaded into the bottom lug. The brass colored stuff is a special spacer and buffer made of a special alloy. The gas gun system can be made either with or without a barrel bushing. The gas piston is held in position by a threaded retainer that fits into the slide where the recoil spring plug normally is located.

The gas gun barrel looks very much like the common "ramped" fully supported chamber .38 Super barrels.