9x23mm Steyr crimp

9mm Steyr was developed for M1912 pistol (below). The lower row has a variety of loads from different countries. But the upper row has a single FN round with a primer crimp. Why?

Was this the cartridge used in the Steyr-Solothurn SMG?..Pete.

Thanks. So the crimped ones are for SMG. Are they loaded hotter? Are they OK to use in my pistol?

Vlad, no one here should give you advise what is safe in your pistol unless they are certified gunsmiths and able to examine your pistol in a way to certify it’s safety to fire ANY ammunition.

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Sorry, let me re-phrase it. Was ammo made for Steyr-Solothurn loaded/manufactured any differently than ammo made for M1912? Are they interchangable?

Read posts carefully…peteC asked a question, he did not provide you any information for you to make the conclusion that you did.

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Ok, I got it. I was just following a usual logical path. SMG’s have heavier action and usually require more force for recoil which is achieved by greater amount of propellant. In many posts before it was mentioned not to use machine gun loads in regular rifles. I also read up on Steyr-Solothurn (which I never owned), and it said that it was an exceptionally well made SMG. So I wondered if it required hotter load. Maybe not if it is so good. I know close to nothing about SMG’s.

Vlad, your confusion shows clearly, why “hotter” loads of pistol ammunition rarely exist: in the end no soldier knows what is what.
I strongly recommend to never shoot ammunition of unknown origin at all, except after it has been measured in a test barrel for pressure and velocity. Even so, it is highly probable that the primers are corrosive, which could ruin the barrel of your precious M12 in no time.
Why not buy Starline 9 mm Steyr cases for modern Boxer primers and load yor own, non-corrosive, safe-pressure cartridges?

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To return to the interesting matter of the crimped primer: does anyone have an idea why this particular pre-WW2 (as it seems) FN produced round of 9mm Steyr has primer crimps? FN prewar pistol cartridges are overwhelmingly with non crimped primers, as was virtually all the production of other manufacturers. Why this one? Jack

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Could it be as simple as “if the customer wants it, we can do it”?
That would explain them on 7.65 Brownings also…maybe.

That explanation occurred to me and it’s a good one. I’d think FN would have obliged; they weren’t in business to turn down reasonable customer requests. Jack

Looked through mine & found two otherwise the same but with & without the crimps.
With the crimps weighed 184.8 grains & without weighed 182.1 grains
perhaps case / bullet & etc could account for the 2.7 grain difference?

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Another explanation could be that the components for that FN Steyr round with primer crimps could have been sold to another country that actually loaded the cartridges. It could even be a combination of another country ordering the components, to include specifying a crimped primer, while loading the cases in the country that ordered them.

There is a instance of this concerning FN and the caliber 9 mm Browning Long Cartridge. The cartridge in question was actually loaded by Ammunitionsfabrken Marieburg, in Sweden, on May 25, 1940. It is not known when the components were received there, with the bullet, case and primer being made at FN as so noted on the box label. The loading date at Marieburg is only 5 days after the Germans occupied the FN factory at Liege, May 20, 1940. The case has four equidistant and equal-length longitudinal primer crimps. If the cases were sent by FN primed, they would have likely done the crimps themselves. If sent there as all individual components, then they could have been applied at Marieburg at the time of cartridge assembly.

All interesting theories for both the 9 mm Steyr and 9 mm Browning Long rounds, but only that, unfortunately. We will not really know the “why” of the very seldom primer crimping on FN pistol rounds unless some documentation such as a work order, factory drawing, etc., is found, if ever.

Re: IAA Journal 443, May/June 2005, “The 9m/m Browning Long Cartridge - Part 1,” Woodin Laboratory, compiled by John Moss, p.10.

John Moss


John: Thanks for the interesting information on the Swedish Browning long. Pending the arrival of factory documentation it might be suggestive of what happened (or at least for whom it was done) by knowing what kind of packaging the Steyr crimped rounds were found in. Jack