Modern Firearms - Ammunitions

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Special purpose small arms ammunition of USSR and Russia. © 2005 - 2008 Maxim Popenker SP-3 and PZAM silenced pistol ammunition During the postwar period, there was much development in the field of the small arms ammunition. Soviet Union actively participated in these developments, following both mainstream and some more or less unconventional routes. The mainstream developments are well known and included 7.62x39 M43 and 5.45x39 M74 intermediate ammunition for assault rifles, as well as 9x18 ammunition for pistols. Of cause, there was much more development in these lines that it might appear at the first sight, but for now we will focus on rather more interesting types of ammunition. During the post-war decades both USSR and its major rivals from NATO were deeply engaged in espionage and counter-espionage. These activities sometimes called for very special actions, usually described by typical Russian euphemism as “wet deeds”, or, in plain language, murders. These clandestine operations required some very special weapons, and during early 1950s the designer Igor Ya. Stechkin (better known as an author of the 9mm APS Stechkin automatic pistol ), developed a very special weapon for KGB. Externally this weapon looked much like flat tin cigarette case, but internally it held three short barrels and a trigger unit. The intended use of this weapon was obvious, but the necessary compact size effectively prohibited the use of a standard silencer. As a result, Stechkin developed a special type of ammunition, which required no silencer to be fired silently. The major source of the sound of gunshot is the large volume of hot gases, violently expanding from the muzzle and creating a sound wave. Stechkin avoided this problem by encapsulating the blast of the propellant within the cartridge case. First experiments were conducted using standard 9x18 cases, but the ammunition, designated SP-1 (Spetsialnyj Patron 1 – special cartridge 1), never achieved production status. The SP-2 ammunition, which was the first to be produced in any quantity, has been based on 7.62x39 case, slightly shortened and fitted with round-nose 7.62mm bullet with aluminum core extended back into the case to rest on the internal piston. Internally this cartridge contained a small charge of propellant behind a short piston, which propelled the bullet out of the case when fired and then locked the hot powder gases inside the case. The resulting sound was almost non-existent, and the cartridge has been adopted by KGB for clandestine operations. To improve performance and somewhat confuse possible investigators, the round-nose bullet has been later replaced by standard pointed 7.62mm bullet originally used in 7.62x39 M43 ammunition. Earlies development centered on a large steel case with single-stage piston and internal firing pin, located in the base in attempt to keep high pgas pressures within the case after the discharge. This design was known as 7.62x63 PZ cartridge, which later evolved into PZA and PZAM cartridges of the basically same dimensions. This ammunition was in use since mid-1960s in S4M silent pistol . Later on, another cartridge cartridge, designated as 7.62x38 SP-3, has been developed and put in use during early 1970s, along with MSP two-barreled derringer type pistol and NRS scout shooting knife. The SP-3 featured much shorter case, because it used more compact two-stage piston system and more or less standard primers, securely crimped into the base of the cartridge. The performance of the SP-3 was about 25% less (in terms of muzzle energy) than of PZAM, but it was considered sufficient for its intended use in deep concealment last-ditch weapons used by Soviet secret intellegence agents outside of USSR. cartridge metric designation bullet weight muzzle velocity muzzle energy PZAM 7.62x63 8 g / 123 grain ~ 175 m/s / 570 fps 122 J / 90 ft-lbs SP-3 7,62x38 8 g / 123 grain ~ 150 m/s / 490 fps 90 J / 66 ft-lbs loaded 7.62mm PZA loaded 7.62mm PZAM 7.62mm SP-3 cartridge and spent Modern Firearms - Ammunition - Special purpose cartridges of US... http://world.guns.ru/ammo/sp-e.htm 1 of 5 15.7.2010 01:53

Transcript of Modern Firearms - Ammunitions

Page 1: Modern Firearms - Ammunitions

Special purpose small arms ammunition of USSR and Russia.

© 2005 - 2008 Maxim Popenker

SP-3 and PZAM silenced pistol ammunition

During the postwar period, there was much development in the field of the small armsammunition. Soviet Union actively participated in these developments, following bothmainstream and some more or less unconventional routes. The mainstream developmentsare well known and included 7.62x39 M43 and 5.45x39 M74 intermediate ammunition forassault rifles, as well as 9x18 ammunition for pistols. Of cause, there was much moredevelopment in these lines that it might appear at the first sight, but for now we will focuson rather more interesting types of ammunition.During the post-war decades both USSR and its major rivals from NATO were deeplyengaged in espionage and counter-espionage. These activities sometimes called for veryspecial actions, usually described by typical Russian euphemism as “wet deeds”, or, inplain language, murders. These clandestine operations required some very specialweapons, and during early 1950s the designer Igor Ya. Stechkin (better known as anauthor of the 9mm APS Stechkin automatic pistol), developed a very special weapon forKGB. Externally this weapon looked much like flat tin cigarette case, but internally it heldthree short barrels and a trigger unit. The intended use of this weapon was obvious, but thenecessary compact size effectively prohibited the use of a standard silencer. As a result,Stechkin developed a special type of ammunition, which required no silencer to be firedsilently. The major source of the sound of gunshot is the large volume of hot gases,violently expanding from the muzzle and creating a sound wave. Stechkin avoided thisproblem by encapsulating the blast of the propellant within the cartridge case. Firstexperiments were conducted using standard 9x18 cases, but the ammunition, designatedSP-1 (Spetsialnyj Patron 1 – special cartridge 1), never achieved production status. TheSP-2 ammunition, which was the first to be produced in any quantity, has been based on7.62x39 case, slightly shortened and fitted with round-nose 7.62mm bullet with aluminumcore extended back into the case to rest on the internal piston. Internally this cartridgecontained a small charge of propellant behind a short piston, which propelled the bullet outof the case when fired and then locked the hot powder gases inside the case. The resultingsound was almost non-existent, and the cartridge has been adopted by KGB forclandestine operations. To improve performance and somewhat confuse possibleinvestigators, the round-nose bullet has been later replaced by standard pointed 7.62mmbullet originally used in 7.62x39 M43 ammunition. Earlies development centered on a largesteel case with single-stage piston and internal firing pin, located in the base in attempt tokeep high pgas pressures within the case after the discharge. This design was known as7.62x63 PZ cartridge, which later evolved into PZA and PZAM cartridges of the basicallysame dimensions. This ammunition was in use since mid-1960s in S4M silent pistol. Lateron, another cartridge cartridge, designated as 7.62x38 SP-3, has been developed and putin use during early 1970s, along with MSP two-barreled derringer type pistol and NRSscout shooting knife. The SP-3 featured much shorter case, because it used morecompact two-stage piston system and more or less standard primers, securely crimpedinto the base of the cartridge. The performance of the SP-3 was about 25% less (in termsof muzzle energy) than of PZAM, but it was considered sufficient for its intended use indeep concealment last-ditch weapons used by Soviet secret intellegence agents outside ofUSSR.

cartridge metric designation bullet weight muzzle velocity muzzle energyPZAM 7.62x63 8 g / 123 grain ~ 175 m/s / 570 fps 122 J / 90 ft-lbsSP-3 7,62x38 8 g / 123 grain ~ 150 m/s / 490 fps 90 J / 66 ft-lbs

loaded 7.62mm PZA loaded 7.62mm PZAM 7.62mm SP-3 cartridge and spent

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loaded 7.62mm PZAsilent cartridge and fired

case (note projectingpiston)

loaded 7.62mm PZAMsilent cartridge and fired

case (note projectingpiston and slightly

bottleneckedcartridge) loaded intosteel clip, as used for

S4M pistol

7.62mm SP-3 cartridge and spentSP-3 case and bullet, loaded into

steel clip used for MSP pistolNote that piston is of two-stage

telescoped design

SP-4 silenced ammunition

The key problem with the SP-3 and PZAMammo were their telescoped pistons, whichprojected significantly from fired cases andthus made almost impossible to develop thesemi-automatic weapons for thesecartridges. During late 1970s and early1980s Soviet designers solved this problemby developing the 7.62x42 SP-4ammunition, which used the same basicprinciple. The telescoped two-stage pistonhas been replaced by single-stage piston,which did not projected from the case whenfired; the standard 7.62mm M43 bullet hasbeen replaced by the cylindrical bullet, madeof mild steel, and fitted with a brass drivingband at the front. This cartridge has beenadopted circa 1983 by KGB and Spetsnazelements of the Soviet Army, along withsix-shot, magazine fed, blowback operatedsemiautomatic PSS pistol and single-shotNRS-1 scout shooting knife. The SP-4ammunition and PSS pistols are still in useby elite Spetsnaz units within Russianarmed forces, as well as by some FSB andMVD elite units. Apparently, the earlier MSPpistol with SP-3 ammo and S4M pistol withPZAM ammo were not phased out ofservice and still can be encountered in thehands of serious operators, who not requiremulti-shot capabilities of PSS / SP-4system.

cartridge metricdesignation

bulletweight

muzzlevelocity

SP-4 7.62x419,3 g /

143grain

200 m/s/ 655 fps

7.62mm SP-4 silent cartridge (left)compared to 9x19 Parabellum cartridge(right)

SP-5 and SP-6 subsonic assault rifle ammunition

Next line of development, also initiated bySpetsnaz requirements, also involved silencedweapons, but in more powerful form. Since theeffective range of silenced pistols is severelylimited, scout and Spetsnaz elements of the Sovietarmy originally employed AK and AKM rifles, fittedwith detachable sound suppressors (silencers) andloaded with special versions of 7.62x39 M43ammo, known as 7.62x39 US (UmenshennayaSkorost – Low velocity). To achieve subsonicvelocity along with acceptable ballistics, thesecartridges were loaded with heavier bullets, but itsperformance was still inadequate. So, during thelate 1980s, soviet designers developed improvedsub-sonic ammunition, suitable for speciallydesigned automatic weapons. These cartridges,known as SP-5 and SP-6, were based on a7.62x39 M43 case, necked-out to 9mm, and loadedwith heavy, streamlined bullets. The SP-5 cartridgewas loaded with standard “ball” bullet with lead core,and was intended for accurate sniper work out to300-400 meters. The SP-6 cartridge featured anarmour-piercing bullet with hardened steel core,which could defeat typical military type bodyarmour at the ranges of up to 300-400 meters. Twoweapons were initially developed for thisammunition, both based on the same receiver andgas operated action – VSS sniper rifle and AS

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gas operated action – VSS sniper rifle and ASassault rifle. Both weapons were selective fired,with integral sound suppressors, and used samemagazines with 10- or 20-round capacity. Latter on,several more weapons were developed for 9x39ammunition, such as SR-3 and 9A-91 compactassault rifles, used by elite Internal Affairs Ministry,Police and State Security units. The one problem,associated with 9x39, as well as with most otherspecial purpose cartridges, is that such ammunitionis usually quite expensive. An attempt was madeduring late 1990s to produce much cheaper 9x39AP loading, designated as PAB-9. This cartridgefeatured bullets with stamped (instead of machined)steel cores, as well as increased driving surfaces.As a result, accuracy was poor and barrel wearsignificantly increased, so this ammunition isapparently no longer in use.

cartridge metricdesignation

bulletweight

muzzlevelocity

7.62 US 7,62x39 12,5 g /193 grain

290 m/s /950 fps

СП-5 9x39 16,8 g /260 grain

280 m/s /920 fps

СП-6 9x39 16 g / 247grain

280 m/s /920 fps

left to right: SP-5 ball cartridge caseand bullet; SP-6 AP dummycartridge, and 7.62x39 M43 cartridgefor scale

SP-10 armor piercing pistol ammunition

This development leads us back to pistolammunition, but this time with improvedpenetration capabilities rather thanstealth. The proliferation of body armorrendered most military pistols, with itsammunition being about 100 years old,almost obsolete. The one way to dealwith body armor is to adopt smaller-caliber, high velocity bullets for bothpistols and submachine guns. This givesadditional benefit of flatter trajectory andlessened recoil, both beneficial foraccuracy. At the minus side, the terminalperformance of the small-caliber, lightweight bullets is somewhat questionable.After initial test and research, conductedsince late 1980s under the codename“Grach”, Russian armed forces adoptedan improved version of the world’s mostpopular pistol ammo, the 9x19Parabellum. First produced circa 1994,this version of the 9mm features anarmor piercing bullet of proprietarydesign, and a powerful powder charge,which brings this cartridge, officiallydesignated as 7N21, to the +P+ level,with peak pressures running up to 2 800kg per square meter. Armor piercingbullet for 7N21 ammo features ahardened steel penetrator core, enclosedinto bimetallic jacket. The space betweenthe core and jacked is filled withpolyethylene, and the tip of the penetratoris exposed at the front of the bullet, toachieve better penetration. Bullet of thesimilar design, but of lighter weight, isused in another service 9x19 cartridge,7N31, which has been developed in late1990s for the GSh-18 pistol, and latterwas adopted for PP-2000 submachinegun. Another offspring of the ”Grach”trials is the 9x21 family of ammunition.Adopted by the Federal Security Bureau(FSB) of Russian Federation, thiscartridge in its basic form, known asSP-10, is more or less a stretched-out7N21 cartridge with improvedperformance; 9x21 ammo also available

9mm SP-10 AP cartridge (right) compared to9x19 Parabellum cartridge (left)

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in AP-T (tracer) and SP-11 low-ricochetball (with lead core) bullets. This ammo isused in SPS “Gyrza” pistol and in SR-2“Veresk” submachine gun.

cartridge metricdesignation

bulletweight

muzzlevelocity

7N21 9x195.3 g /

82grain

460 m/s/ 1508

fps

7N31 9x194.2 g /

65grain

600 m/s/ 1967

fps

7N28 /SP-11 9x21

7.9 g /122grain

390 m/s/ 1278

fps

7N29 /SP-10 9x21

6.7 g /103grain

430 m/s/ 1410

fps

Underwater pistol and rifle ammunition

Next line of development, almost unique to the Sovietarmed forces, is the underwater firearms and ammunitionfor these. Initially developed during late sixties, underwatercartridges propelled the long and slim drag-stabilizedbullets, and were used in four-barreled SPP-1 break-openpistols. To achieve better loading and extraction, thebottlenecked brass cartridges were rimmed and loadedusing special flat clips, which held all four rounds together.Both primer pockets and case necks were sealed againstthe water, and the steel bullets were covered by speciallacquer coating. Initially satisfied with the pistol, SpecialForces elements of the Soviet Navy requested furtherdevelopment and by the mid-1970s soviet designersbrought in an unique underwater assault rifle, the APS(which, in fact, was a smoothbore weapon). This weaponused cartridges, externally similar to earlier SPS pistolammunition, but based on the standard 5.45x39 M74cases. This “rifle” ammunition is available in two basicforms, MPS “ball” and MPST “tracer”. Both APSunderwater automatic weapon and SPP-1M underwaterpistol are still in use by Russian navy, as well as offeredfor export.

cartridge metricdesignation

bulletweight

muzzlevelocity

SPS 4.5x40R 13.2 g / 204grain

250 m/s / 820fps

MPS 5.66x39 15 g / 232grain

360 m/s /1180 fps

Note: for underwater cartridges muzzle velocities listed inair; in the water, MV depends on the actual depth

underwater cartridges, left toright:

7.62x39 M43 cartridge forscale;

4.5mm SPS cartridge caseand bullet;

4.5mm SPS dummycartridge;

5.66mm MPS dummycartridge

Small-caliber pistol ammunition

The last development, which could beconsidered as a “special purpose”, tookthe place during 1970 – 1972 timeframe,when the KGB requested thedevelopment of an “easily concealablepocket pistol, with flat shape and notthicker than a matchbox (17mm)”. Thispistol was intended as a concealed carryweapon for security personnel, as well asself-defense weapon for top rankedofficials. After a short research designersrejected available western “pocket-gun”ammunition, such as 6.35x16SR and7.65x17SR, as entirely unsatisfactory,and rapidly developed a small round,which looked more or less like scaleddown 7.62x39 M43 cartridge. The5.45x18 MPTs cartridge had a rimlessbottlenecked case, made of brass, with

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bottlenecked case, made of brass, withpointed jacketed bullet. The terminalperformance of this tiny cartridge israther unspectacular, but it has areputation for penetrating soft bodyarmor at shorter distances. However, it isby no means an “armor piercing”ammunition, and the latter attempts touse it for larger PDW-type weapons suchas full-size OTs-23 “Drotik” automaticpistol, turned into a predictable failure.Still, the extremely compact and quitereliable 5.45x18 PSM pistol is widelyused as a self-defense weapon for Armyand MVD generals, as well as by variouslaw enforcement operatives, workingunder cover.

cartridge metricdesignation

bulletweight

muzzlevelocity

7N7 /5.45mmMPTs

5.45x172.5 g /

39grain

320 m/s/ 1050

fps

5.45mm 7N7 cartridge (right) compared to9x19 Parabellum cartridge (left)

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