This will be my last response on this thread, as neither of us can convince the other of his point of view, and it must be quite boring for those not that interested in the myriad of variations of the 9 x 19 mm cartridge, precisely the caliber designation assigned these Simunition marker AND OTHER TYPES made by them, which you are ignoring. I am well aware of the function of these cartridges - I have some 30 specimen variations in my own collection, as well as one inch thick of material on this ammunition in my library. My collection includes a fired case to show its increased length upon firing, where the two-piece case acts like a short-stroke piston to operation the mechanism of self-loading weapons.
It is clear to both of us that the bullet diameter was reduced for safety reasons that I need not revisit here. The oriignal bullet diameter of the Simunition 9 x 19 mm, cartridge type FX, was approx. 8.78 mm, just measured from a specimen with a high-quality digital caliper. The collar on this two-piece case is, by the way, made of steel, not plastic like all later models. Case length is 19.42 mm, slightly longer than the length designated by Simunition in their catalog designation of the cartridges, perhaps an early and continuing safety measure, before they applied a plastic collar with a smaller diameter bullet, approximately 6.92 mm in diameter. The plastic-collar ammunition has approximately the same case length as the initial version with steel collar.
Question - if the caliber designated by the manufacturer as 9 x 19 is not the full caliber designation, and you feel FX is part of the caliber designation rather than a description of the cartridge type (among various other types they manufacture, including even conventional Frangible 9 x 19 mm cartridges), than why is the designation of the second and finalized type not “7mm FX,” since great importance in the designation of the diameter of the projectile seems to be stressed here? The early version, therefore, should have been designation as the 8.7 mm FX, again according to beliefs expressed here.
As C.I.P. Tables, they are free to call a cartridge anything they want. They are not an organization with which I am particularly impressed, an opinion that has been expressed to me as well by several European ammunition specialists.
You are absolutely correct that a 9 mm shortened case was used, but it is a composite case, where the collar forms the upper part of the case, as well as functioning as a short-stroke piston. We are all well familiar with other composite case types. In truth, this two piece case is longer than a normal 9 mm case, as mentioned above.
If your argument about caliber designation is correct, then we must accept that the factory that designed and manufactured this ammunition, and refers to all of the various types as 9 x 19 followed by the initials expressing the specific TYPE of the cartridge, were incorrect in that designation. Since those cartridges with the 9 x 19 mm designation are specifically made to be used with 9 x 19 mm Pistols and Machine Pistols, fitted with a conversion kit for safety reasons, I do NOT believe that the manufacturer was incorrect.
I will continue to classify these rounds as 9 mm LUGER (Parabellum) types, even though I have a moderately fair collection of all calibers of cartridges, not just 9 x 19 mm, so could classify them as anything else I believed was correct, and would not lose them out of my collection.
Others are, of course, free to classify them as they wish.
Again, I see no point in continuing this disagreement over a minor point of classification, in deference to the other members of the Forum who likely find this discussion of no interest at all. I regret starting it, in truth.