...A handsome arm you have there in a bit of a unique caliber.
...Your rifle is very close to my beloved 6.5 X 55 Swedish Mauser. These calibers are fantastic for deer sized game.
I saw a couple 6.5x54 MS over the years in vintage stutzen rifles by Mannlicher Shoenauer...As far as I know, Hirtemberger still load it. It's a nice little round that witness the value of a 6.5mm bullet was discovered indeed a lot of time ago...
The 6.5X54 rimless was a proprietary cartridge created for the M1900 Mannlicher Schoenauer prototypes that were built by Oesterreichische Waffenfabriks-Gesellschaft Steyr (OWGS) and introduced at Paris' Exposition Universelle of 1900. It was a rimless version of the 6.5X53R (.256 Mannlicher) used in previous Mannlicher military arms which were fed via the 'Mannlicher Packet Loading System' (en bloc clip). The rimless version was introduced to feed through the Schoenauer rotary magazine. Both cartridges are loaded the same and have identical ballistic characteristics.
En bloc with 6.5X53R
Schoenauer magazine with 6.5X54MS
Greece adopted the Mannlicher Schoenauer as Y1903 and continued to purchase them as revised Y1903/14, Y1903/14/27 ('Breda'), System 1930, and variants, all of which were chambered for the MS proprietary 6.5X54 cartridge.
As Y1903 production began in 1905, Steyr also produced the sporting version, M1903, in half stocked rifle, stutzen (full stocked carbine), and take down form as well as model M1905 with its own MS proprietary cartridge of 9X56. These were soon joined by models of M1908 and M1910 with their proprietary cartridges of 8X56 and 9.5X57, respectively.
The MS will feed through its Schoenauer magazine with a smoothness that made it legend
if the cartridges are loaded at or very close to original specifications of overall length and with the proper round nosed projectiles.
If you want it to perform flawlessly, load or have cartridges loaded to these dimensions: