22 scamp

From the 1970s we have the 22 SCAMP (Small CAliber Machine Pistol) intended to replace the M1911 45 ACP as a close quarters personal defense weapon. From Colt, the gas-operated, autoloading pistol was chambered for a cartridge firing a 40 grain, 22 caliber bullet at 2100 fps. Prototype cartridges were made from re-formed 22 Hornet cases. Once the desired ballistics were obtained a contract was let for 1000 new cases and bullets to be loaded by Colt. (One source says only 500 of each were manufactured). Most of the cartridges were fired during testing making both prototypes very rare. It’s reported that only one prototype pistol was made. In the end, the concept was rejected by the military.

Below are shown the two prototype cartridges flanked by the 22 Hornet and 221 IMP, and the headstamps of each.

Very nice! Am I right in thinking that the Colt-headstamped round was actually made by Industrie Valcartrier Ray?


I have here a cartridge that needs ID…Looks alot, or maybe exactly, like the one on the right in your photo, headstamp is just R - P


Randy, I suspect your cartridge might be the 1963 experimental .222 High Velocity. It’s very similar to that pictured by Ray but has a slightly shorter bullet with a bit of a flattened tip and an open nose.

Thanks, Jim…

I can ID any Krag from about 10 feet, but I am useless on the more modern military items…what you describe is exactly what I have…


The SCAMP cases and bullets were made by IVI.

Here’s a bunch of 221 look-a-likes including the 222 Hi Velocity.

What are the case dimensions differences between the 221 Rem and the 221 Imp ?
They look identical


They are the same. The IMP is loaded with a a 5.56mm M196 tracer bullet with no tip color. It has a copper primer and is headstamped R-P 221 REM.