8×63mm patron m/32

The 8×63mm patron m/32 was a bottlenecked centrefire cartridge with a slightly (0.25 mm (0.0098 in)) rebated rim for Swedish heavy and medium machine guns. It was used from 1932 to the finalization of the re-chambering process of these machine guns to 7.62×51mm NATO in 1975.

8×63mm
Two 8×63mm patron m/32 military cartridges
Type	Rifle
Place of origin	Sweden
Service history
In service	1932–1975
Used by	Sweden
Wars	UN intervention in Kongo 1960-1964
Production history
Designer	Royal Swedish Army Materiel Administration (KAF), AB Bofors
Designed	late 1920s, early 1930s
Manufacturer	AB Bofors
Specifications
Case type	Rimless, bottleneck
Bullet diameter	8.20 mm (0.323 in)
Neck diameter	9.10 mm (0.358 in)
Shoulder diameter	11.51 mm (0.453 in)
Base diameter	12.43 mm (0.489 in)
Rim diameter	12.18 mm (0.480 in)
Rim thickness	1.42 mm (0.056 in)
Case length	62.81 mm (2.473 in)
Overall length	84.62 mm (3.331 in)
Primer type	Large rifle
Ballistic performance
Bullet mass/type Velocity Energy 9.72 g (150 gr) FMJ 930 m/s (3,100 ft/s) 4,203 J (3,100 ft⋅lbf) 11.0 g (170 gr) FMJ 860 m/s (2,800 ft/s) 4,068 J (3,000 ft⋅lbf) 14.2 g (219 gr) m/32 FMJ 760 m/s (2,500 ft/s) 4,101 J (3,025 ft⋅lbf) 14.6 g (225 gr) FMJ 747 m/s (2,450 ft/s) 4,073 J (3,004 ft⋅lbf)
Test barrel length: 609 mm (24 in) Source(s): [1]

In the late 1920s, the standard service cartridge in Swedish use was the 6.5×55mm Swedish skarp patron m/94 projektil m/94 (live cartridge m/94 projectile m/94) service ammunition loaded with a 10.1 grams (156 gr) long round-nosed m/94 (B-projectile) bullet which was not considered effective enough for anti-aircraft and indirect fire so the Royal Swedish Army Materiel Administration tasked AB Bofors to manufacture a larger rifle cartridge to meet these needs.

Left; 8×63mm patron m/32 cartridge
Right; 7.92×57mm Mauser cartridge
with 14.2 g (219.1 gr) m/32 and 11.55 g (178.2 gr) S.m.E. 8 mm S bore bullets

The patron m/32 round had the same overall length as the .30-06 Springfield cartridge, which allowed it to fit in the standard Browning receiver, but used a larger diameter case and like the 6.5×55mm had an uncommon 12.2 mm (0.48 in) diameter bolt face. Compared to the 1928 pattern .30-06 Springfield M1 Ball the 8×63mm patron m/32 was loaded with 8 mm S bore 14.2 g (219.1 gr) bullets and had more muzzle energy.[2]

The patron m/32's boat-tailed spitzer bullets had an effective range of approximately 3,600 m (3,937 yd) on which the impact energy was 196 J (145 ft⋅lbf), and a maximum range of approximately 5,500 m (6,015 yd) when fired from a kulspruta m/36.[3] Available with armour piercing bullets, patron m/32 was used in the UN-forces' KP-bil during the Congo-crisis against the separatists' armoured cars.

The 8×63mm patron m/32 cartridge was used in the following machine guns:[4]

• Kulspruta m/22
• Kulspruta m/14-29
• Kulspruta m/36
• Kulspruta m/39
• Kulspruta m/42

The 8×63mm patron m/32 was also used in the gevär m/40 bolt-action rifle. These were Karabiner 98k's re-chambered in Sweden for the patron m/32 and issued to the machine gun troops so their rifles would fire the same round as their machine guns. There are statements the gevär m/40 originally was intended as a stop-gap anti-tank rifle, but this has yet to be confirmed.