You don't need a gunsmith to tell you that the cartridge for the Modelo Argentino 1891 or Modelo Argentino M 1909is the 7.65X53mm Mauser round. (BUT, it isa good idea to have a gunsmith check the HEADSPACE on any old military rifle before it is fired. Unless the previous owner has been shooting it with no problems!)

This particular cartridge WAS designed by Paul Mauser, UNLIKE the 57mm-long ones of various calibersthat are all based on the 7.8X57mmJ (8X57J) cartridge which, although called "the 8mm Mauser", is not a Mauser cartridgeat all, but was designed by the Prussian Infantry Rifle Commission, along with the Gewehr 1888 rifle. Paul Mauser favored cartridges SHORTER than 57mm. That's why this one is only 53mm long. The 7.65X53mm roundwas used by Argentina, a couple of other latin American armies, Turket & Belgium at least. Belgium used it in their M1889 rifle, which has the same single-row protruding magazine box in front of the trigger guard as does the Modelo Arg. 1891.

Funny thing is that all the later "Mauser" cartridges using 57mm-long cases to shoot bullets ranging from .224 all the way up to 9.3 are made by necking the M1888 Commision cartridge up and downand calling them "Mauser", when they weren't Mauser desgns at all...........