Very strange gyrojet

weird 13mm gyro jet with a alloy nose plug painted red and a weird wax coating on the back…alos looks to be a mis fire as the wax is mesed up and the primer looks pierced.WHAT IS IT ? Thanks.

If any gyro collectors want it let me know as I am not a gyro collector.


Your 13mm gyrojet was made from a length of copper-plated steel tubing called “Bundy” tube, which was used in the automobile industry for high-pressure hydraulic brake lines and such. It could be bent without kinking; a big advantage, and it is still in use today, mainly in air-conditioning and refrigerator systems. If you look carefully, you’ll see the soldered seam running lengthwise from the base to the tip. The tubing is formed from a flat piece of copper-plated steel rolled over into a tube shape and soldered closed. It was very cheap, which is why MBA liked it. It would also hold the pressure.

When the gyrojet case was formed, there was a small hole left at the tip, and MBA closed this by using an aluminum rivet inserted as the nose was being formed. Robert Mainhardt told me that the red tip meant nothing. It was just added on some of these to make them look different, or “sexy.” At the time, MBA was trying to sell its gyrojet firearms and rockets to collectors, and you know that cartridge collectors love color tips.

When these were being made in the late 1960s, MBA also did a lot of work on different ways of waterproofing the rockets, and one of the things they tried was to coat the base with wax, as with your specimen. This didn’t work, for a number of reasons.

Is your gyrojet’s primer snapped? Sometimes, the wax just flakes off after a few years…40 years in this case.


yes…I see the seam. You very smart on these THANK YOU !

The primer is snapped I can see the dent …misfire ???


Could be a misfire.

The gyrojet uses a primer very similar to a centerfire cartridge primer and it is ignited by the gyrojet weapon in much the same manner as a centerfire primer.

An indication that the gyrojet has been fired is the dent in the center of the primer which is located at the center of the base. The hole in the was seal in your photo is the approximate location of the primer.

I have seen a number of gyrojets being sold or auctioned with a dented primer. This is where is necessary to ask questions or read the descriptions very carefully to know if the specimen has been fired or is live.