One of the most unusual and least known surplus military rifles you might encounter is the Siamese Type 45 Infantry Rifle or commonly called the Model 1903 Siamese Mauser that was used by Siamese/Thai military during the early and middle Twentieth century.

History/Design

As Siam, later changing its name to Thailand in 1938, was one of the few independent South Eastern Asian states that was not under direct European rule in the late Nineteenth Century they had decided to modernize their army to hold on to the last of their territories that had not been seized by the British or French. As both of these nations were not willing to sell large numbers of arms to the Siamese the government of Siam decided to acquire weapons from their rivals, Germany and the Austro-Hungarian Empire, in which they purchased a number of Gew. 1871 Mausers from Germany and Gew.1888, 1888/90 and 1895 Mannlichers from Austria-Hungary. In late 1899 or 1900 the Siamese decided to upgrade its military with a new state of the art weapon and looked to Mauser's new Gew. 1898 as its new weapon of choice. The weapon they ultimately decided to adopt in 1903 was the Siamese Type 45 Infantry Rifle, or as some collectors call it the Type 46, but we will leave that for others to debate due to the complexity of the Siamese calendar.

 

Note

The Siamese/Thai calendar starts with the birth of Buddha and in our Christian year 1903 it was the year 2445 to the Siamese

The basic design of the weapon is almost an exact duplicate of the Gew.1898 Mauser, but due to the fact that the Royal Siamese Arsenal in Bangkok did not have the facilities to manufacture complete rifles they turned to Japan, which had been a natural ally and seeking closer ties due to being a fellow independent nation as well as increased military influence, to manufacture the weapon for them. The weapon therefore had some uniquely Japanese features to it, as well as some of Mannlicher features. The weapon was made by the Imperial Japanese Army Arsenal at Tokyo (Kowisikawa) but there was a small number of German made Model 1903 Siamese Mauser's that are marked 1901, along with the Siamese crest on the receiver bridge, that was made at Waffenfabrik Mauser but these were believed to be the prototype rifles that the Japanese could have used to copy and manufacture these weapons.

 

The receiver shown with the sliding dust cover in the open position

There were about 400,000 of these weapons made from 1903 until production ceased in 1908. It has a two piece tang in the top and bottom of the pistol grip to help reinforce the stock in the wrist area against breakage, a magazine floor plate that is easily removable by pressing a catch in the forward part of the trigger guard thus releasing the floor plate from the trigger guard housing, and a sliding dust cover on the top of receiver that was held in place by rails built into the receiver that had to be manually operated back and forth by lifting a latch on the cover to disengage it from the notches that held in place in the receiver thus allowing it to be moved.

 

The receiver shown with the sliding dust cover in the closed position

This cover was copied from the one used on the Japanese Type 35 Rifle. The stocks on the weapons were of a fat-bellied design and are sometimes found with Japanese style two piece stocks in which the bottom of the butt was a separate piece of wood that was dovetailed and glued to the upper part. Some are found with one piece stocks and it is believed these were replacement stocks made by the National Armory in Bangkok at a later date.

 

The top of the chamber showing the stamped "Charka" and model designation of R.S. 121

Another strong Japanese characteristic was the bolt handle which had a thin shaft and an odd shaped grasping ball. All the other features of the rifle, bolt, receiver, sights and magazine are definitely pure Mauser which featured the one-piece, cock-on-opening bolt with dual frontal locking lugs and safety lug on the rear of the bolt body, the non-rotating extractor, and the gas escape holes to help direct the gases down the left bolt lug way and out the thumb clearance cut out in the receiver in case of a ruptured case or pierced primer.

 

The weapons serial number

The left side of the receiver showing the Imperial Japanese Army Arsenal at Tokyo (Kowisikawa) marking

The front sight, front barrel band and the bayonet lug What is missing is the cleaning rod

The front and rear sights were the type found on the Turkish Model 1903 Mauser. Unlike a vast majority of military Mausers which were chambered for the rimless cartridges, this weapon was the only one that was chambered for a rimmed bottleneck cartridge so the magazine box had to be of a slanted, staggered column type to prevent the cartridge rims from catching each other. Mannlicher's influence can be seen in the cartridge (described below) and the knife type bayonet which appears to be a copy of the one used by M95 Mannlicher Rifles. A unique feature of the weapon was the butt-plate which had a sliding cover plate that held the front sight/muzzle cover that was made of brass in the stock when not being used. (It is a common misconception that this held an oilier or cleaning equipment) These weapons were made of quality materials and showed signs of first-class workmanship.

 

The rear barrel band (I understand that this barrel band was later used on the Brazilian 1908 Mausers)

The bolt

The sliding cover plate on the buttplate in the opened position

The Siamese government also made extensive modifications to the Model 1903 Siamese Mausers to obtain short rifles and carbines configurations at later dates and one of them is the Type 46 Carbine. This weapon was of a shorter length with a 20.5-inch barrel, side mounted sling swivels on the barrel band and left side of stock The barrel and muzzle bands on this particular weapon were very similar to those found on the Japanese Type 38 that in fact it used the standard Japanese Type 30 bayonet. Approximately 12,500 of these weapons were made.
All of these weapons were used in the Franco-Thai War of 1940-41 that took place in the Battambang province (Cambodia) of French Indochina during WW2.

Markings

Stamped on the top of receiver ring is a "Charka", meaning circle or loop, which was an ancient Thai throwing weapon which was considered a “weapon of the gods“. Below this, in Siamese script is inscribed R.S. 121, which translated to Ratanakos 121 which signified that the weapon was adopted in the 121st year of the reign of the Ratanakosin Dynasty under the rein of King Rama V (1868-1910) in the Christian year 1903. On the receiver bridge are the numerals, in Siamese script, that make up the weapons serial number. Graduations for elevation on the rear sight base and leaf are also in Siamese scripted numerals. On the left wall of the receiver just in front of the thumb clearance cut out is the Tokyo Army Arsenal symbol, three stacked cannonballs. If you disassemble the weapon you will find stamped underneath the receiver, and all other parts a one to three digit number and a Japanese Katakana symbol, which is the assembly number assigned that weapon by Tokyo Arsenal. Sometimes you will find weapons that have the Siamese markings, serial numbers and rear sights ground off and re-stamped with Arabic numberings on them.

 

The one piece buttstock

The rear sights

The bottom of the weapon showing the magazine floor plate

The rear sight base, notice this one has been cut down for the 8x52Rmm Type 66 cartridge

The Siamese Mauser Bayonet and Scabbard

The markings on the bayonet which also bear the inscription R.S. 121

Ammunition/Modification

The weapon was originally chambered for the 8x50Rmm Siamese Type 45 (2445) cartridge which was adopted in the year 1902 a full year before adopting the Type 45 Infantry Rifle, these were for used in the Steyr made Model 95 Mannlicher Rifle that was exported to Siam. The bullet was a round nosed, lead cored, cupro-nickel clad, full metal jacket design that weighed 237 grains and had a diameter of .321-inch with an approximate muzzle velocity of 2050 fps. The cartridge case was made of brass with a Berdan primer and on the bottom of the cartridge case it is marked with the numbers 45 in Siamese script. Only ball bullets were used. This cartridge was made in both Japan and at the National Arsenal in Bangkok. Note: The Siamese Type 45 is not interchangeable with the Austrian 8x50Rmm cartridge even though that round was used as a basis for the development of the Siamese Type 45 cartridge.
In the early 1920's the Siamese wanted to upgrade the Type 45 cartridge to a more powerful and pointed type of round for use in their Browning F.N., Vickers and Madsen Machine Guns and the Type 45 was not suitable for this, thus they developed the 8x52Rmm Siamese Type 66 cartridge. The 8x52Rmm Siamese Type 66 cartridge was adopted in 1923 (2466), using a spitzer boat-tail bullet, lead cored, a gilding-metal or copper-washed steel jacket design that weighed 181 grains and had a diameter of .323-inch with a muzzle velocity of 2250 fps. The cartridge case was made of brass with a Berdan and later Boxer primer and on the bottom of the cartridge case it is marked with the numbers 66 in Siamese script. Ammunition was also made in Tracer, Armor Piercing (AP) and Armor Piercing Incendiary (API). This cartridge was made at the National Arsenal in Bangkok until 1953, Japan, England (Kynoch), Denmark and Finland (Sako).
When the Type 66 cartridge was adopted, most 1903 Siamese Mausers were re-chambered and/or re-barreled to handle this cartridge. When the weapons were converted the rear sight base was cut down to give the correct elevation with the new ballistics of the Type 66 flatter trajectory, thus taking off some of the original sight graduations. This is the easiest way to tell that the weapon has been converted to the new round. It was also common practice for Japanese Arsenals to put a second assembly number on rifles that had to be rebuilt, thus you can find some of these converted weapons with two assembly number and Katakana symbols. This second assembly number is placed on the bottom of the receiver just above the original assembly assigned number. If the conversion took place at the National Armory in Bangkok it lacks the second assembly number. On some of weapons the trigger guard is usually marked with a 66 indicating that the magazine box has been converted to accept the longer Type 66 round and other parts of the weapon might also bear the 66 markings. It has been debated if the barrels on these conversions are re-chambered or re-barreled as most of the time the barrels look like they are newer to the weapon itself as the rear sight bases on them are usually pitted and the barrels are not.

 

Top: 8x50Rmm Type 45: Adopted in 1902 (2445) it is a 237 gr., .321-inch diameter cupro-nickel clad, full metal jacket, round nosed bullet. Approx. Muzzle Velocity: 2050 fps

Middle: 8x52Rmm Type 66: Adopted in 1923 (2466) it is a 181 gr., .323-inch diameter lead core with a gilding-metal steel jacket, spitzer boat-tail bullet. Approx. Muzzle Velocity: 2250 fps

Bottom: 8x52Rmm Type 66: case-formed cartridge

Conclusion

These weapons remained standard issue with the Siamese (Thai) military from 1903 through to the early 1960’s when they were eventually replaced with small arms that were provided by the U.S. military. Most of these weapons were sold to the various U.S. importers in the middle 1960’s but some remained in Thailand were they were used by the National Police and were re-chambered to use the 30-06 cartridge and from what I understand some of these were in service until the late 1980’s.

Patrick Hernandez