Mauser-Vergueiro was a bolt action rifle, designed in 1904 by José A. Vergueiro, Infantry officer of the Portuguese Army. It was developed from the rifle Mauser 98 with the introduction of a new bolt system. Out of Portugal, the weapon was also known as Portuguese Mauser. It used the 6.5x58mm Vergueiro, a portuguese cartridge developed specially for it.

The weapon substituted the Kropatschek m/1886 as the standard infantry rifle of the Portuguese Army in 1904, remaining itself in service until the its substitution, for the Mauser 98k in 1939. In the Portuguese service the weapon was officially designated Espingarda 6,5 mm m/1904 (Rifle 6.5mm m/1904). A lighter and shorter version of the weapon was classified as a carabine and designated Carabina 6,5 mm m/1904. Mauser-Vergueiro was also in the service of Brazil and South Africa.

In Portuguese and South African service it was used in combat in the First World War and in several colonial campaigns. The German colonial troops in East Africa also used Mauser-Vergueiro rifles, captured from the allied forces in combat, preferring them to its proper Mauser rifles of German origin.

In 1939, already after the Portuguese Army have adopted the 7.92x57mm Mauser 98k, a version of Mauser-Vergueiro modified for that type of the ammunition was introduced . This version was called Espingarda 8 mm m/1904/39.

The Portuguese Model 1904 Model 1939 Mauser-Vergueiro rifle started out as the Portuguese Model 1904 Mauser-Vergueiro cal 6.5 mm rifle that was developed by Verguerio, a Portuguese Officer. During the late 1930's Portugal adopted the Model 937-A Mauser rifle chambered in the 8mm Mauser cartridge. Portugal then converted most of the stocks of the Model 1904 rifle by shortening the barrel and fore-end, modifying the front sights, and reboring and rechambering the rifle to shoot the 7.92x57mm (8mm Mauser) cartridge. The 1903/39 bolt is a true oddity to be found in a Mauser rifle as it is a Mannlicher type bolt and not a typical 98 style bolt. Some of the features of the bolt are dual-opposed forward locking lugs, a separate bolt head, and no bolt sleeve. The 1903/39 bolt is one of the most complex to disassemble and reassemble.

Service history
In service 1904–1937
Used by Portugal, Brazil, South Africa, German East Africa
Wars World War I
Production history
Designed 1904
Produced 1904–1945
Variants Rifle m/1907, Carbine m/1907 and Rifle m/1907/39
Specifications
Weight 3.9 kg (Rifles m/1904 and m/1904/39)
3.6 kg (Carbine m/1907)
Length 1110 mm (Rifles m/1904 and m/1904/39)
1100 mm (Carbine m/1907)
Barrel length 600 mm
Cartridge 6.5x58mm Vergueiro (Rifle and Carbine m/1907)
7.92x57mm Mauser (Rifle m/1907/39)
Action Bolt-action
Muzzle velocity 715 m/s
Effective range 2000 m
Feed system 5-round stripper clip, internal magazine