Wednesday, March 28, 2012

Intermediate power ammunition for automatic assault rifles

5.45x39 Soviet

This cartridge was originally developed during late 1960s as a direct rival to the US 5.56x45 M193 carttridge then in use by US Army. Originally it featured a long, low-drag bullet with mild steel core and a hollow cavity in the nose to provide optimum balance, and a laquered steel case. This version was adopted in 1974 and oficially designated in USSR as 5.45mm 7N6. Later on, this cartridge was generally replaced in production in Russia by 7N10 ammunition, which has improved penetration thanks to harder steel core. Other bullet types in the 5.45x39 range of military ammunition include tracers, armor piercing and subsonic cartridges (for use by Spetsnaz troops in silenced AKS-74UB compact assault rifles).
The 5.45x39 is still a general issue caliber in the Russian military and a few of other ex-USSR republics. In most other the ex-Warsaw pact countries this caliber was gradually replaced in service with 5.56x45 NATO ammunition and appropriate weapons.

Designation Bullet weight, g Muzzle velocity, m/s Muzzle energy, J Comments
5.45x39 7N6 3.43 880 1328 bullet with mild steel core
5.45x39 7N10 3.62 880 1400 bullet with enhanced penetration
5.45x39 7N22 3.68 890 1430 armor-piercing bullet with hardened steel core
5.45x39 7U1 5.2 303 239 subsonic, for use with silenced AKS-74UB compact rifle only

5.56x45

The story of this cartridge begins in around 1950, when US Army initiated the study in small arms effectiveness, that culminated in famous ORO reports by Hall (An Effectiveness Study of the Infantry Rifle) and Hitchman (Operational Requirements for an Infantry Hand Weapon). Among other conclusions, these reports called for weapon with effective range of about 300 yards, with controlled pattern dispersion of hits in bursts, to improve hit probability. One of proposed solutions was to create burst-firing small-caliber weapon firing conventional projectile.  In 1952, an M2 carbine re-barreled to experimental .22 caliber round (based on shortened .222 Rem case) was studied and found promising. Various other rounds with .22 caliber projectiles, based on .30-06 and T67 (.30 / 7.62 NATO) were tseted as well. In 1957, the Armalite Ar-15 rifle, firing the newly developed .222 remington Special cartridge was tested, and in 1959 the .222 Special cartridge, developed to fulfill new military requrements for 500 meters effective fire, was renamed to .223 Remington (as a commercial offering). In 1961 US Air Force and ARPA requested a number of .223 caliber Ar-15 rifles, and military service of the new round commences in early 1962, when US AF standartised Ar-15 rifle as M16. US Army adopted the .223 cartridge as 5.56x45mm in 1963, and Remington commercially introduced the .223 as a hunting round in 1964.
Following the problems with 7.62mm M14 rifle and protracted delays with SPIW program, the M16 rifle and its .223 caliber (5.56x45) ammunition was adopted as a next US Military infantry rifle system. After much field use in Vietnam and elsewhere, and extensive trials, an updated version of the .223 cartridge, loaded with heavier SS109 bullet of Belgian design, was officially adopted in 1979 as a new NATO round, known as 5.56x45 NATO. Recent issues with insufficient stopping power of M855 5.56mm NATO ammunition in Iraq and Afghanistan (especially when firing from short-barreled carbines) resulted in development of an even heavier loading, the Mk.262, with bullet of enhanced ballistic and striking performance. Many other types of projectiles also available for this caliber in 'military' versions, ranging from blank and short-range tpractice and up to armour-piercing and tracer. The variety of civilian versions (intended for small-game hunting, plinking, target shooting and self-defense) is almost infinite, and this round is produced in many countries. Great many weapons, both military and civilian, are available for this caliber.

Designation Bullet weight, g Muzzle velocity, m/s Muzzle energy, J Comments
5.56x45 M193 3.5 991 1750 from standard assault rifle barrel (20")
5.56x45 M885 4.15 930 1790 from standard assault rifle barrel (20")
5.56x45 M885 4.15 880 1600 from carbine barrel (14")
5.56x45 Mk.262 5 895 2000 from standard assault rifle barrel (20")
5.56x45 Mk.262 5 772 1490 from carbine barrel (13")

5.8x42 DAP-87

This is a relatively new cartridge, developed by Chinese experts during mid- to late 1980s. Today it is a main infantry cartridge in the PLA, which is chambered in assault rifles, light and universal machine guns and sniper rifles. For latter applications (machine guns and sniping) a long-range version was developed that features heavier bullet and higher pressure load. It is believed that this long range version might replace standard version as a general issue ammunition, which apparently displayed unsatisfactory medium- and long-range performance in PLA use.

Designation Bullet weight, g Muzzle velocity, m/s Muzzle energy, J Comments
5.8x42 DAP-87 4.15 790 1290 standard military ball bullet from carbine barrel
5.8x42 DAP-87 4.15 930 1790 standard military ball bullet from standard assult rifle barrel
5.8x42 DAP-87 5 895 2000 heavy ball from machine gun or sniper rifle barrel

6.5 Grendel (6.5x39)

This cartridge was developed in around 2002 to provide Ar-15 type rifles with long-range capabilities and terminal effectiveness that are generally not possible with standard 5.56 mm / .223 ammunition. The 6.5 Grendel is based on .220 PPC cartridge, developed for shooting matches, which in turn is based on Soviet 7.62x39 catridge case. The 6.5 Grendel provides longer range and better terminal effectiveness over the 5.56x45, thanks to heavier bullets with better balistics. The price for this improvement is somewhat stronger recoil (although it's still noticeably less than that of 7.62x51 / .308), and decreased magazine capacity (due to a larger diameter case). The 6.5 Grendel is viewed by many as an 'ideal compromise' assault rifle round, although today its practical use is limited mostly to civilian applications (hunting, target shooting, self-defense). This cartridge is manufactured in USA and Serbia, and weapons for it produced mostly in USA.

Designation Bullet weight, g Muzzle velocity, m/s Muzzle energy, J Comments
6.5 Grendel 5.8 880 2250 Speer TNT bullet
6.5 Grendel 8.0 820 2600 Sierra MK bullet

6.8 Remington SPC (6.8x43)

The 6.8mm Remington is another attempt to produce an 'ideal' assault rifle cartridge which would provide good terminal effectiveness (stopping and killing power) from short, carbine barrels out to 300 meters, while having dimensions and recoil close to 5.56x45 NATO (which lacks terminal effectiveness, especially when fired from short carbines). This cartridge was commercially developed by Remington with collaboration from some members of US Special forces, and the 6.8mm ammunition and weapons were apparently tested by US Military, but none were adopted so far. The 6.8 Rem SPC is, to certain extent, a direct rival to the 6.5 Grendel round described above. Today, the 6.8 Rem ammunition is manufactured commercialy in USA, and few weapons are available to fire this round.

Designation Bullet weight, g Muzzle velocity, m/s Muzzle energy, J Comments
6.8 Rem SPC 7.45 800 2390 from 61cm / 24" rifle barrel
6.8 Rem SPC 7.12 785 2200 from 40cm / 16" carbine barrel

.30 M1 carbine (7.62x33)

This cartridge was born in 1940 from the US Army's "Light Rifle" project, which was intended to provide military personnel (that is normally not issued with standard rifle) with handy carbine instead of the very marginally effective handguns. The project succeeded, and great many carbines and cartridges for them were made during WW2 and shortly afterwards. This ammunition was extensively used during WW2 and Korean war, but after that it's use rapidly declined. Originally it was chambered in only one type of mass-produced weapon, the US M1 carbine (and its variations M1A1, M2 and M3). Several countries (i.e. France and Italy) attempted to produce experimental assault rifles for this cartridge in late 1940s, but none succeeded. The only weapons of relatively recent design and manufacture to fire this cartridge are Israeli "Magal" police rifle and Brazilian Taurus TC-30 carbine (also intended for police use). Ammunition in this caliber is still loaded commercially as there's still many M1 carbines around in civilian hands. Few handguns (pistols and revolvers) were built over the time to fire this cartridge, but firing .30 Carbine round from short barrel usually results in extensive (some say: spectacular) muzzle blast and flash.
By modern standards, this round somewhat lacks effective range and power, but it is nevertheless an effective round for police use and self-defense, with effective range being about 200 to 300 meters from a carbine. It also outperforms most common pistol cartridges (i.e. 7.62x25, 9x19 Luger or .45ACP), fired from submachine guns, in terms of muzzle energy (when it is fired from carbine barrel) by about 100% at all practical ranges.

Designation Bullet weight, g Muzzle velocity, m/s Muzzle energy, J Comments
.30 M1 7 606 1300 military ball bullet

7.62x39 M43 Soviet

Development of this round was initiated in late 1943, when Red Army requested development of new, intermediate power weapons to fill the gap between pistol-caliber submachine guns and full-power rifles. This requirement came from studying two then-new weapon systems - German MKb.42 assault rifle and its 7.92x33 cartridge and US M1 carbine and its .30 M1 cartridge. First cartridges were developed in 1944, featuring steel bottlenecked case 41mm long, loaded with pointed, flat-based jacketed bullet with lead core. First weapons for this cartridge were developed in late 1944, and included bolt-action and semi-automatic carbines, light machine guns and automatic (assult) rifles. In 1947 the cartridge case was shortened to 39mm, with introduction of the slightly longer, boat-tailed bullet with mild steel core, and in this form it was adopted for service in Soviet Army. While officially replaced in front-line service in Soviet army by 4.45x39 ammunition in 1974, it was never officially declared obsolete and plenty of 7.62x39 weapons are still in service with Russian army and law enforcement forces. This cartridge also gained widespread acceptance along with appropriately chambered weapons produced in USSR, its former allies and China.
Today this is one of the most widely used military cartridges in the world, with weapons and ammunition produced in many countries and many versions. Huntig versions of the 7.62x39 ammunition are also manufactured in several countries; those usually feature lead-core expanding or non-expanding bullets.

Designation Bullet weight, g Muzzle velocity, m/s Muzzle energy, J Comments
7.62x39 57-N-231 8 710 2010 Standard military ball bullet with mild steel core
7.62x39 7N23 8 730 2130 Armor-piercing bullet
7.62x39 US 12.5 300 562 Subsonic, for use with silenced AKM rifles

7.62x45 Vz.52

This cartridge was developed during late 1940s and early 1950s by Czhechoslovak military experts, and originally was chambered in just two weapons - Vz.52 semi-automatic carbine and Vz.52 light machine gun. A true assault (automatic) rifle for this cartridge was still in the works when Czhechoslovak army was forced (under Warsaw pact standartisation agreements) to replace this round with slightly less powerful 7.62x39 M43 round of Soviet origin.
Today thsi round is obsolete and its production has long been completed.

Designation Bullet weight, g Muzzle velocity, m/s Muzzle energy, J Comments
7.62x45 Vz.52 8.4 744 2325 military ball bullet

7.92x33 PP Kurz

Developed in 1940 by Polte company in Germany, this cartridge is usually quoted as the first practical intermediate power assault rifle cartridge, although it had significant number of predecessors (experimental military cartridges and certain medium-power commercial hunting cartridges). This cartridge was extensively used in MP.43/ MP.44 /  Stg.44 assault rifles by German army during WW2, and by the Yugoslavian paratroopers and East German police after WW2. No new military weapons to fire this ammunition were ever made since WW2. This cartridge was produced in Yugoslavia until early 1980s, and small batches of newly made cartridges still appear on the commercial markets from today's Serbia, to satisfy collectors who still own and shoot WW2-era guns. For all practical purposes it is considered obsolete, although its historical significance cannot be underestimated.

Designation Bullet weight, g Muzzle velocity, m/s Muzzle energy, J Comments
7.92x33 PP Kurz 8.1 686 1900 military ball bullet

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