The so-called "Commercial 1920 and 1923 " designations are thoise developed and promoted by the Luger/Parabellum collector fraternity, and perpetuated in several “serious” Luger Collection Books. (printed in the 1960s)
After WW I, Germany was not permitted to make 9mm Pistols, so many Lugers were refurbished or new made, in 7,65 Parabellum Calibre. ( for Civilian Sales, both in Europe, and for export.).
The 9mm Dutch Luger Contract of 1923, was actually assembled by Vickers on DWM-made Parts, as were several “other” early 1920s Contract 9mm Lugers, by other “non-German” assemblers. ( Vickers had a long standing relationship with DWM going back to the Maxim and Loewe Days ( 1890s).
In the US, the “Commercial” Lugers were retailed by Stoeger’s, which had registered the Trademark “Luger” within the United States ( DWM had always referred to Luger’s design Pistol as the “Parabellum” ( from its Berlin telegraphic address from the 1890s.))
Blank firing a Luger: Due to the Knee-Toggle design of the action,the only way to succesfully get a Pb to funcvtion in SA fire is to change the geometry of the Recoil "hump"at the back of the frame.
Some were “butchered” by welding a bead to change the slope of the Hump, thus making it easier to the Toggel to unlock with even slight recoil…this combined with a weaker spring, allowed the back-pressure and a little recoil to operate the mechanism. This method was often beset by failures to feed properly on the return stroke, due to the weakened spring)
The other (“Non destructive”) manner ( except for the screw-in restrictor vent) is to make a thin metal ring, to fit over the Toggle dishes, to increase the diameter, and thus the Toggle (Knee) is never fully Locked, so that on firing, the back pressure will cause both the Slide to recoil and the Lock to open and eject the shell, and with a normal recoil spring, recharge the action for the next shot.
The heavily roll crimped and wadded shell is due to a Postive lock-in for the laquered card wad, in order that it was firmly in place, and so the Powder could fully combust and give sufficient pressure to cause recoil ( “jet effect” thru restrictor vent).
This has been overcome in Post-1960s Blanks by the star-crimp method of blank closure, which allows for full combustion of the Powder.
Remington seems to have been the major supplier of Movie Blanks from WW I into well after WW II ( I have Stembridge Packets of the 1950s, ( Over-labels on Remington packets) of .45/70 and “8mm Mauser” Blanks.
The .45/70s still function, but the majority of the “8mm” are kaputt.
And of course, the Ubiquitous “5-in-1” by Rem, now supplied as Loadable cases by Starline.
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