Spanish Cartridge Mystery Solved

Over a year ago a Spanish reader emailed me to ask about the strange cartridge he found (pictured above). It had a ~7.62mm sized rifle bullet in what looked like a 9mm pistol cartridge case. Carlos wrote …

I recently moved to my grandmother‘s house in Madrid to start my university studies. I am sleeping in my uncle‘s old room. While I was looking in the wardrobe, I found a box full of cartridges, probably picked up by my uncle while doing the mandatory military service. Between them I found an odd looking one. It is marked 7.92×24.5 FNM-78. I think that he did the military service around the year 1978, that might have to do something with the markings. The round is quite strange looking. It looks like an 8mm mauser bullet in a necked down pistol case. I have never heard of any such ammo being used in the spanish army or in any firearm. It might be an experumental PDW round or something like that. I am sending you a picture of the cartridge compared to a 7.62 NATO case and a 9mm largo round next to the actual bullet and case separated. The bullet looks like a standard ball bullet with lead core.

I was not able to identify it, but Carlos persisted. He wrote in an email to me a few days ago …

I finally found the answer! It is meant to be used in a training insert for the M20 rocket launcher in Portuguese service and the INSTALANZA 88,9 mm rocket launcher in Spanish Army service. There are two versions of it, one with a 7.92 mm bullet and another with a 7.62 mm bullet.

The weakly propelled 7.62mm rifle bullet must be a ballistic match for the rockets fired from Spain’s Instalza 88.9mm M65 rocket launcher.


Instalza 88.9mm M65 rocket launcher


Thanks Carlos for sharing that info with us.

Steve Johnson

Founder and Dictator-In-Chief of TFB. A passionate gun owner, a shooting enthusiast and totally tacti-uncool. Favorite first date location: any gun range. Steve can be contacted here.


  • bbmg

    This sort of thing is exactly is why I follow this blog 🙂

    • milo


  • reniswiss

    Something similar does exist for the Panzerfaust used by Swiss Armed Forces. They insert a special barrel into the Panzerfaust and shoot very low velocitiy rounds trough it. The rounds have tracer-bullets, so the path of flight can be seen. Pretty cool.

    • justin

      the Marines Mk153 SMAW also has a ballistically matched spotting rifle. 9mm tracer crimped into a 7.62×51 casing and a .22 hornet blank for propellent.

    • bbmg

      There is also a 20mm attachment for the Carl Gustav.

  • Sounds like the AT-4 tracer trainer that shot 9mm tracer rounds that had the same arc as the AT-4 rocket. Cool blog, really interesting

  • Cuban Pete

    The Spanish Army had a long love affair with RCL weapons.

  • Carlos

    Hi, thank you a lot for blogging it, it was a pleasure to do the research and sharing it!

  • Beaumont

    Thanks, Carlos. I find things on this blog that I never see anywhere else.

  • Laserbait

    Looks like a JD Jones Whisper variant.

  • Yves
  • Tony Williams

    There is a wide range of this type of tracer/flash ammunition. Some of it is intended for low-cost training, others as spotters to judge the right aiming point before firing the main weapon (these can also be used for training, of course). There’s a pic of my small collection of them here, from the Ammo Photo Gallery on my website:

    The key to the photo: 7.65×21 (Erika Pak 75),7.92×24.5(Portuguese),7.62×25(Instalaza),7.62×27 (Swiss),7.62×33(Argentine),7.5x55R (Swiss),7.62×24(Portuguese),9×51 (SMAW Mk 217), 10x43B(US XM75),12.7×76 (.50 Spotter), 12.7×99(British .50 BMG for use in Centurion tank), 14.5x21R(artillery trainer),14.5x51R(artillery trainer),15×99 (USA),15.2×120 (15mm XM122 USA), 20x22R(Netherlands),20x45R (USA),20×126 case(XM101 for Davy Crockett)

  • Zermoid

    I never thought of rockets as having an arc, at least until their fuel was expended…..