This is a 7.5 x 54.5 Schmidt-Rubin GP 08 experimental, as confirmed by the headstamp, according to Cartridge Head Stamps of Switzerland 1867-1985, by Michael am Rhyn. The case manufacturer is T = Selve Thun, Switzerland and the material was supplied by D. = Düren, Germany. The object of the experiment was do develop a new rifle to replace the ageing M.90 and M.90/03’s. The projectile is of Cupro Nickel, it has a lead core construction and a flat base as shown below. The abovementioned book states that the dates found on these experimental loadings range from 12/1908 to 7/1911. The first GP 11 headstamp, with the new spitzer projectile of more conventional design, is shown as 1/1912, five months after the last GP 08 headstamp. This case was loaded with the old M90/03 projectile, seen here without the paper patch with CN cup. An explanation that has been suggested is that this case was also used for standard military issue at the time with the M90/03 projectile that was in use until the then new GP11 projectile was standardized. (see also RSACCA 2886/214/16)

However, as early as 1903 there were discussions regarding the adoption of a lighter, easier to handle rifle with an improved cartridge. One of the main factors were the severe ballistic shortcomings of the 89/96 action / GP90 cartridge combination. The Swiss Rifle Commission gave permission to Waffenfabrik Bern to create 200 rifles for testing purposes late in 1907 and these were made as follows:
– 50 rifles with 1889/96 Barrels firing the M.90 cartridge,
– 50 rifles with 1889/96 Barrels firing the M.90 cartridge, bored-out chamber,
– 50 rifles with 1889/96 barrels in the new caliber GP 08, (which later evolved into the GP11) with a reworked chamber,
– 50 rifles with newly formed barrels for the new GP11

Other modifications included the removal of the magazine cut-off, improved sights, and an internal rifle rest. While the internal rest was discarded as superfluous, the testing otherwise proved successful. This led to the authorization for the manufacture of 900 Rifles and 100 Carbines, for the purposes of testing the new GP08 (later redesignated as the GP11) cartridge. The 1908 Rifles and Carbines were fitted with Model 1889/1900 style 6 round magazines, and improved sights. The 1908’s also had several unique features, not found in other Schmidt-Rubin models, like the locking lug sleeve of the 1908’s bolt had three circular holes, presumably for weight savings purposes, as well as the relief cuts on the top of 1908s receiver were of different length, with the longer cut set along the center of the receiver, with the shorter cut off to the side. (see also http://www.fshombergbuchen.ch/schmidt-rubin-1896-11.html)

It can be argued therefore that the improved bullet was an outflow of the original ballistic tests after the Swiss knew by late 1907 that the old M.90/03’s were inferior to the newer designs from their European neighbours. The spitser bullet was also widely used by then by the Germans and the French.

Rubin M.1896/11 conversion.