[1][2] Through various modifications, adaptations, and using various cartridges, the Siamese Mausers served as the main infantry weapon of Siam until after World War II.

[1][2] Many countries yielded to pressure from France and Britain and refused to sell Siam modern weapons.

[1] The Siamese military was able to buy out a defaulted Bulgarian contract for Austrian Mannlicher Model 1888/90 rifles.

[1][3] They decided against adopting the Mannlicher, straight-pull bolt action, but the Siamese were impressed with the Austrian 8×50mm rimmed cartridge.

[1] Despite British and French efforts, Siam also managed to buy a license to build Mauser's Gewehr 98 rifle.

Some features and characteristics of the Japanese Type 35 rifle (under development in the same arsenal at that time) were also incorporated, such as the sliding dust cover and long wrist tangs.

The wings of the sight ramp was inscribed with Thai numerals, possibly representing meters, with the highest number being ๒๐ (20, for 2000m).

As a result, many of the Thai numbers inscribed on rear sight ramps are partially cut-off.

Although dimensionally similar to the Mannlicher round they favored from earlier rifles, the 8×50mmR Siamese was unique to Siam and was not interchangeable with the Austrian ammunition (Siamese ammunition chambers and can be fired in Austrian rifles but not vice versa).

[1][3][4] The Type 45 cartridge fired a round-nosed bullet typical of main military battle rifles at the time.

[1] After the French introduction of the spitzer bullet in the 8×50mmR Lebel rimmed cartridge in 1898, other countries followed suit.

In addition to a spitzer bullet, the Type 66 ammunition was approximately 2mm longer, making it an 8×52mm rimmed cartridge.