In the period 190x to 1914 etseq., Argentina participated in the Pan American shooting Games.
During the 1912 Games, the Argentine Navy team was impressed by the .30-06 Springfield Rifle and Cartridge, and decided tio develop a 7,65 calibre cartridge to replicate .30 cal performance at long ranges, and using the current DWM M1909 Mauser Rifle, with a 7,65mm Bore.
To make a Cartridge that would fit and Feed with a simple re-chambering, they developed an 7,65x54 case, extended to 7,65x61, with the extension fitted in, in the body, so that the shoulder neck profile was identical in dimensions.Development work was done in conjunction with WRA.
Initially bullets were 7,65mm 154 grain FB, and later ( WRA make) were 175-180 Boattail on the Swiss GP11 pattern.
Sample Rifles were modified re-chambering, fitted with US1903 Pattern Rearsights,( calibrated in Meters for new Cartrige) and Stock patterned on US M1903 Stock, at least in Butt and wrist area.
See Photo of said Match rifle ( unidentified as to use) in Ball’s Mauser Rifle Book, in the Argentine Section.
After WWI, it is unknown how long
the 7,65x61 MA was in service for, and how many M1909 DWMs were converted and/or restocked for Match Use. Being a Navy Marksmanship thing, I suppose very few.
Any Clues, Fede?