Silent 9x19mm-Steel Bullet


About 20 or more years ago, the Agency had a truly silent 9x19 produced. The concept was similar to one used many years ago on a truly silent 30-06 cartridge. The cartridge case had a second brass case/liner silver-soldered inside. The space between the two cases was filled with powder. When fired, the inner case/liner expanded down the barrel and mechanically pushed the bullet out the bore. The inner case encapsulated the gases from the burned powder so no gases went down the barrel and the only sounds were the mechanical sounds of the firing mechanism and the barrel moving down the barrel.

Below is a photo of the loaded cartridge, the fired case and the bullet. These are not in my collection, though I do have a fired case.

The original bullet was truncated. This development is at least 20-30 years old, and probably older, going back to Vietnam. The cases have commercial R-P headstamps.




So these were intended for an agent to silently shoot through a car, a window, a door, or a wall I take it, and while using a standard 9mm pistol of any type without a silencer attached? And I assume that is a band of lead around the projectile? Very Interesting!



Very unusual shape to the bullet. Can you tell us more about the purpose of the “tail” or the material used for the rotating band?


The rotating band is plastic, as it was on the truncated bullet. The tail on the bullet wis there for the case liner to mechanically push on the bullet as the liner unfolded from inside the case and expanded down the barrel. I have seen drawings from many years ago of an identical load in 30-06.

I have no idea what the intended use was for this cartridge (tunnel rats, whatever) or what weapon it was intended to be used in. I have to believe the velocity was pretty low (of course it would be subsonic) so I suspect it would not operate an automatic pistol, but that is only guesswork.

Cheers, Lew


I actually found one of the projectiles a few years back in the dig-box of an old-timer. Not knowing what it was, I played a trick on another collector-friend. I had his wife give it to him, telling him it was a rare “tit-fire” round I couldn’t identify. Well…long-story-short…he happened to know what it was, and the sight of his eyes bugging out and jaw hitting the floor told me I must have found something interesting. The entertainment was well-worth the few bucks I paid for it, and my friend ended up with a real prize also.


What is the significance of “silver” in silver soldering the inner liner? Why silver?


Vlad, the better solder is silver based and should give better results.


the limited warefare lab at APG did work on silent revolvers for tunnel rat use on this principle, it is possible these come from that.


No, these were produced by AAI in Maryland. All I have is a fired case. It came directly from AAI after an old friend had some people search to see if there was anything left there, and it came from the desk of an oldtimer who worked the project. Jon, I’m still looking for a bullet just in case you find another!!!

Aberdeen had nothing to do with this as far as I know.




I guess anything’s possible. I thought you got the one I found from Dennis.


Not yet, but I’ve only removed three fingernails so far!


Once this cartridge has been fired does the sealed case reamain permanently pressurised with gas? For emaple, if you were to puncture the fired example shown, would high pressure gas escape from it?


Soldering is a high temperature operation, even hotter with silver soldering. So the liner must have been soldered in place before the propellant and primer were added. How was the propellant then placed between the case and the liner, through the primer pocket?



The concept of a gas sealed propelling round was first used by Aircraft Armaments, Inc. in 1959 for cartridge actuated devices. Due to its “silent” characteristics this design was later exploited for projectile rounds like Lew’s 9 mm and 12 ga.

These drawings were published in three different patents issued to AAI:


AAI tried this in many applications including tool cartridges for use in space. The only application which showed great success was in the silent 40mm grenades of which there were several types. The “captive piston and captive charge” designs both suffer from the same limitation; short range.


I have seen documentation on a similar silent 30-06 (bit different design) dated in the 1950s. The idea has been around a while.




Looking at the photo with the 9mm case and bullet - I am trying to figure out how they fit together and ultimately function? Is the fired case with the bulging pusher “ballooned” out and was it originally inverted when it had the bullet loaded into the case? Does firing cause the powder to pop that thing out and invert like a balloon thus pushing the bullet out? I just didn’t see how the thing would fit in the case with the bullet’s tail as well…


Fede, the earliest patent for captive noiseless ammo that I have in my collection dates back to 1902, it’s US 692,819

as for the 9mm in question, i doubt that it will eject reliably (or even eject at all) from any conventional 9mm autoloader


Bissell 1902 patent is of a different design employing a pusher piston obturator and does not involve a flexible element.

Silent .30-06 from 1960 was also a pusher-piston type:



The pressure of the gas is dependent upon its temperature. As it cools the temperature will drop rapidly.