9mm Largo Corrosive/Non-Corrosive

I was wondering if anyone knows when the 9mm Largo from Pirotechnia De Sevilla went from corrosive to non-corrosive. I’ve tried the search several different ways and will try again, but thought I’d give this a shot also. Cheers, Bruce.

The earliest box label I have from Spain that confirms non-corrosive priming is a 9 mm Largo Box from May 1977. I think it would be safe to say that from that date on 9 mm Largo from that country was non-corrosive. However, these “modern” boxes that I have in 6.35 mm, 7.65 mm Browning, 9 mm Corto, 9 mm Para and 9 mm Largo are all from Santa Barbara-Toledo, so from my collection, I cannot speak to the question of Sevilla ammunition, nor to the exact STARTING DATE of Sevilla OR Toledo non-corrosive primer use.

According to the book “Cartucheria Española” by Molina and Orea, the last run of 9 mm Largo in Spain by any of the factories was in December 1981. I could find no where in the book where they address the question of the date of change from corrosive to non-corrosive primers. All 9 mm Largo variations shown in the book used Berdan primers, whether corrosive or non-corrosive.

Sorry. I know I have not answered your question, but it is the best I can do on the subject of Spanish non-corrosive pistol ammunition. Have you checked the AECC website yet. Perhaps something can be found there. If not, perhaps one of our Spanish members can chime in here, or perhaps Fede can.

Bruce & John, the Spanish developed non-corrosive primer mixture was designated Tetrinox and was used in 9 mm Bergmann-Bayard/Largo cartridges made by Sevilla as early as 1961. Its presence was identified by means of a green primer sealant.

Thanks for your information, John. The 9mm Largo forum has some 1000 round crates and one of them (1966) is said to be non-corrosive, but the forum didn’t get in to specifics and I had been wondering if it could be narrowed down some.

Fede, Thanks for narrowing it down. Have an open crate with 25 round boxes marked Cargados en Mayo 1963. I’ve unsealed two of the boxes and though they are without green primer anulus, one has 5 rounds headstamped 62 and the other has 9 of them. Odd.

Fede - I can’t dispute, having never subjected any of the Spanish Largo primers to a rust test, your date of “as early as 1961” for Sevilla use of their Tetrinox non-corrosive primers. However, if a green seal (or any colored seal) was the idnetifier for such priming, I would submit that 1963 is a more accurate date. I have the following in my own Largo Collection:

S 9 61 (No colored seals)
S 9 62 (No colored seals)
S 9 63 (Green CMS and Green PA)

T 9-L 61 (No colored seals)
T 9-L 62 (No colored seals)
T 9-L 64 (Red CMS and Red PA)
T 9-L 64 (Green PA only)
T 9-L 65 (Green PA only)
T 9-L 70 (Green PA only)
9-L SB-T 77 (Green PA only)
9-L SB-T 81 (Green PA only)

You will see that for both Toledo and Sevilla, years before 63 do not have green seals. I don’t know the meaning of the red seals; it may simply have been the first color used with a quick decision to switch to green, for whatever reason.

I do not question that the decision to go to a non-corrosive primer may have been made as early as 1961, but again, if a green seal indicates that, then the actual change over was more likely in 1963. I also do not challenge that the green color is an indication of that change. It makes sense.

I hope these comments do not simply further muddy the waters on this question. I have tried to state my opinion clearly and with evidence.

Bacarnal - It is not particularly odd for cartridge cases to be loaded in the following year from their production, or even many years. In the 9 mm Bergmann-Bayard caliber, which is what “9 mm Largo” actually is, in Denmark cartridge cases of several years were produced in very big quantities, and then used a couple (or more) years until they were exhausted. Then some more were made and the process repeated. At least, that is the explanation I got for a very wide spread between case dates, for a pistol that was in issue from 1910 until WW2.

Regarding your mixed-date boxes, though, you did not mention the important feature. Are the boxes factory marked as non-corrosive (which could be “non-corrosivo” or simply “Tetrinox”)? This is important. It will tell you, and us, about the possibilities of your cartridges being corrosive or non-corrosive primed. It would also bear on the question of whether or not all non-corrosive Largo primers were identified by green (or other colored) seals.

Please let us know. Thank you. Interesting stuff. My non-technical mind never thought about this in regard to this caliber, which is a severe oversight on my part since I wrote the book on the 9 x 23 cartridges, and really did not address the corrosive vs non-corrosive issue at all. Mea culpa.

John, I mentioned the 1961 date because there is also a round headstamped S 9 61 with green CMS and green PA. The Toledo factory also made non-corrosive cartridges during this year but I haven’t noted a cartridge with this date and green sealants. The presence of red color sealants identifies a match cartridge.

Fede - then it appears that your date of “61” is valid. I could understand two rounds with the same date with one having no seals and the other green seals, showing most likely a shift to non-corrosive primers during the course of the year. Having one with green seals, and also no seals, and then the next year having no seals. throws me a little. Evidently they were simultaneously loading both corrosive and non-corrosive primers, or at least both in one year and not necessarily with the newest type primer following the older one. Can’t quite envision the reason for that.

John, Sorry for the confusion. None of the boxes for Mayo 1963 are marked either Non-Corrosivo nor Tetrinox, so I had assumed that they were corrosive. Mixed in the case is a box of T 9-L 65 that does have the green PA. The box itself is sterile with no wrap or markings but has the cloth pull loop. I know, doesn’t mean anything. Just describing the box. My interest is piqued. I might have to open the other two cases. Cheers, Bruce.