Swedish 7x57


I just got the following round and would like to know of the green annulus has any load significance:
CNCS, brass case and primer, smooth cannelure on bullet at case mouth, green annulus; SM 6 7x57 6


I suspect that this round was a contract for a South American country. Years ago, I came into 5,000 rounds of Swedish 9mm red-plastic bullet blanks, which I went through for headstamps. I found one round with the same headstamp as your 7 x 57mm, except for the caliber marking of course. It took me years to find a ball round, which came to me from Uruguay by way of an Argentine collector who found it there for me. I don’t know if it was a contract specifically for Uruguay or for some other SA country, but think it was certainly for Latin America. Tjhe calibers in question and the circumstances of my 9mm ball round, suggest that. My 9mms, both ball and blank, are “66” dated as well, not just a coincidence, I would think. Of course, the blank had nothing to do with the contract - it is the standard Swedish blank and represents use of a reject or production over-run case to make a blank, I am sure. Virtually every Swedish 9mm brass-case headstamp was in that lot of blanks I got - at least those that had been made up until the time I got them.


Thanks, John. Think there’s any loading significance to the green primer seal?


Jon - I really don’t know. My 9mm has a greenish seal too, and in that caliber, it could signify the M39 load (the later M39/B has a red seal), but I don’t know in the 7 x 57. It may simply be a water/oil-proof seal - green was common to SM-loaded rounds, including, I think, even some Weatherby cartridges. Or, it could be a color specified by the contractee to signify a ball cartridge. I think the former case is more likely.

Just dawned on me that everyone reading this thread might not know that “SM” stands for “Svenska Metallverken,” a Swedish firm that was absorbed by Norma. Had the cartridge been made for the Swedish military (it would not have been, though, in caliber 7 x 57), it would have had the code “26” or “026” to signify the manufacturer, rather than “SM”, the initials of the factory. The same is true for my 9mm version of the headstamp described by Jon. The Swedish military rounds in that caliber did have the “26” and “026” headstamps.