The more things change, the more they stay the same.
Back in the 1930s Colt decided that their customers needed a less expensive way to practice with their 1911 pistols. Then, like now, the answer seemed to be the lowly but ubiquitous (and dirt cheap) .22 Long Rifle cartridge.
The problem, of course, is that the .22 doesn’t have the power necessary to push the slide back and cock the hammer. The company wanted to maintain the heft and balance of the pistol, so a lightweight replacement slide was out. They’d simply have to figure out a way to make it all work.
The solution came from a convicted murderer named David Marshall Williams. Williams had tremendous mechanical aptitude, and during his time in prison for killing a Sheriff’s Deputy he designed and built four rifles!
What made him a person of interest to Colt was his work on what he called a “floating chamber”. In essence, the round went into a chamber cut into a sleeve, which was free to move back-and-forth inside of, essentially, a second chamber.
The result is what we recognize today as a short-stroke gas piston; specifically, a co-axial annular short-stroke piston. When the round was fired, the gas pressure drove the floating chamber back a short distance, which in turn “slapped” the slide and caused it to reciprocate. It provided enough power to run the heavy 1911 slide (as long as the unit was kept clean!)
The device was sold both as a complete gun and a conversion kit for existing pistols and called the Ace. Today both are highly collectible.
On Imgur I ran across some superb pictures and high-speed video clips (turned into animated GIFs) of an Ace in action. Definitely worth looking at, they’ll give you a perfect understanding of how the system worked!
-=[ Grant ]=-