HK 4.6×30mm

The HK 4.6×30mm cartridge is a small-caliber, high-velocity, smokeless powder, rebated, bottleneck, centerfire cartridge designed for personal defense weapons developed by German armament manufacturer Heckler & Koch in 1999. It was designed primarily for the MP7 PDW to minimize weight and recoil while increasing body armor penetration. It features a pointed, steel-core, brass-jacketed bullet.

Development

The 4.6×30mm cartridge was introduced in 1999 as a competitor to FN Herstal's 5.7×28mm cartridge. Heckler & Koch started the development of a semi-automatic handgun for their 4.6×30mm PDW cartridge, the Universal Combat Pistol (UCP), but canceled it at the prototype stage.

Overview

Compared to standard intermediate cartridges, one can carry more 4.6×30mm ammunition due to the cartridge's lower weight and relatively small dimensions. Also, due to the lower weight of the bullet, aiming in rapid fire is much easier as recoil depends much on the weight of the bullet. CRISAT testing shows that because of the round's smaller diameter and high projectile velocity, body armor penetration is higher than that of traditional handgun projectiles.
A series of tests performed by NATO in the United Kingdom and France indicated that 5.7×28mm was a superior cartridge. The results of the NATO tests were analyzed by a group of experts from France, the United States, Canada, and the United Kingdom and the group's conclusion was that the 5.7×28mm was "undoubtedly" the more efficient cartridge.
Among other points, the NATO group cited superior effectiveness for the 5.7×28mm against unprotected targets and equal effectiveness against protected targets. It also cited less sensitivity to extreme temperatures for the 5.7×28mm and cited a greater potential risk of barrel erosion with the 4.6×30mm. In addition, the group pointed out that 5.7×28mm is close to the 5.56×45mm NATO by its design and manufacture process, allowing it to be manufactured on existing production lines. The group also pointed out that 5.7×28mm weapons are more mature than 4.6×30mm weapons, and the 5.7×28mm FN Five-seveN pistol was already in production at that time, while the 4.6×30mm Heckler & Koch UCP pistol was still only an early concept. However, the German delegation and others rejected the NATO recommendation that 5.7×28mm be standardized, and as a result, the standardization process was indefinitely halted, though both cartridges would ultimately be standardized by NATO with STANAG 4509 for 5.7×28mm and STANAG 4820 for 4.6×30mm respectively.
A 2004 HK presentation claims that 4.6×30mm Combat Steel retains more energy after CRISAT-penetration than 5.7×28mm SS190.

Cartridge dimensions

The 4.6×30mm has 0.87 mL H₂O cartridge case capacity.
4.6×30mm maximum C.I.P. cartridge dimensions; all sizes in millimeters.
Americans define the shoulder angle at alpha/2 ≈ 22 degrees. The common rifling twist rate for this cartridge is 160 mm, 6 grooves, Ø lands = 4.52 mm, Ø grooves = 4.65 mm, land width = 1.21 mm and the primer type is small rifle.
According to the official C.I.P. rulings, the 4.6×30mm can handle up to Pmax piezo pressure. In C.I.P. regulated countries, every rifle cartridge combination has to be proofed at 125% of this maximum C.I.P. pressure to be certified for sale to consumers, referred to as "PE". This means that 4.6×30mm chambered arms in C.I.P. regulated countries are currently proof tested at PE piezo pressure.
Despite the relatively high Pmax the bolt thrust of the 4.6×30mm is on a similar level when compared with traditional service sidearm cartridges.

Cartridge types

The 4.6×30mm ammunition is produced by RUAG Ammotec, Fiocchi, and BAE Systems.

German Army cartridges

; DM11 "Ultimate Combat"
; DM18
; DM21
; DM31
; DM41

Other RUAG cartridges

; Action SX
; FMJ SX
Types not described here are:

SEMI FRANGIBLE SX
AP SX - possibly the same as DM31, as the same reference term is used in an old version of its datasheet
SUBSONIC SX - HK claims that an early version can penetrate the CRISAT target at 90 m.
TRAINING SX - HK claims that an early version can penetrate the CRISAT target at 100 m.
BLANK SX

Others

The "Combat Steel" is an AP round weaker than the "Ultimate Combat". The round was made by Radway Green of UK. Other ammunition mentioned in the 2004 HK presentation without an obvious successor are:

1.7 g Spoon Nose
1.3 g Tracer
1.2 g Soft Frangible
Drill

Heckler & Koch's 2012 website hosts ammunition datasheets from manufacturers of 4.6×30mm ammunition. Of these, a SFN Ram ammunition has a muzzle energy of approximately 525 J that is comparable to 9×19mm rounds.
VBR produces a 4.6×30mm two-part controlled fragmenting projectile that is claimed to increase the content of the permanent wound cavity and double the chance of hitting a vital organ.

Platforms

Name	Country	Type	Note
Heckler & Koch UCP	Germany	Semi-automatic pistol	Cancelled at the prototype stage.
Heckler & Koch MP7	Germany	Personal defense weapon/Submachine gun
ST Kinetics CPW	Singapore	Personal defense weapon/Submachine gun	4.6 caliber as potential conversion from 9mm.
CMMG Banshee Mk4	USA	Pistol/Carbine	First firearm marketed for civilians in 4.6 caliber.
Tommy Built Tactical T7	USA	Pistol/Carbine	MP7 clone marketed to civilians in 4.6 caliber.