[Ron Wood]

A couple of points of clarification here. A 7.65mm cartridge was in fact loaded specifically for the carbine (DWM headstamp 471) having a blackened case to distinguish it from the lesser-powered cartridges for the standard length barrels. It was loaded â??hotterâ? to be able to function the heavier weight of the carbine barrel/receiver assembly. The accelerator spring in the forestock of the carbine was not so much to control the recoil of the hotter round, but to assist in returning the heavy barrel/receiver group back into battery.

On the later carbines produced in the 1920s (and the modern Mauser replicas), this auxiliary accelerator spring was not necessary because these carbines were created with the coil mainspring which could be made sufficiently powerful to function as both the accelerator spring and the leaf spring combination of the old 1902 carbine. I suspect that the 1920 carbines and the Mauser repros would function with a standard round, but not as reliably as with the hotter black cased round.

As far as making a legal 16� barreled carbine, a hotter load is probably a good idea. Not for the purpose of creating 300 H&H Magnum performance in a stocked handgun, but to achieve the aforementioned reliable functioning. As Washbaer has already observed, there is not much point in building a nice shooting carbine replica and then beat the bejeebers out of it with ultra hot loads to the point that all that hard work in building it is destroyed.