Tag: ballistics

Even within the same ammunition system, different projectile weights have a massive effect on external and terminal ballistics. Here we see some of the different weight bullets available in the 5.56x45mm caliber. Different bore diameters give rounds different properties. Despite the fact that all three rounds shown here - 7.62x39, 5.6x39 Russian, and 6.5x38 Grendel (two on the right) - all use the same case base and have virtually the same case capacity, they have very different ballistic properties due to their different bore and bullet diameter. Left to right: .280/30 British, 7.62x39mm M67, 5.56x45m M855, 6.8x43mm SPC XM68GD, 6.5x38mm Grendel 123gr Lapua Scenar, 7.92x33mm Kz.Ptr.43 sME. All of these rounds have different characteristics that affect their ballistic performance and their reliability in automatic firearms. We'll be taking a closer look at these characteristics to better understand the trade-offs in small arms ammunition design. 7.65x35mmMAS Four PDW calibers: .22 WMR (Kel-Tec CMR-30 and PMR-30 SMG), .22 SCAMP (Colt SCAMP), 5.7x28mm FN (FN P90), and 4.6x30mm HK (HK MP7).

Modern Personal Defense Weapon Calibers 002: The 4.6x30mm HK

If the 5.7x28mm FN is the first successful modern PDW round, then the 4.6x30mm HK is the second, and its biggest rival. German firm Heckler and developed the microcaliber 4.6mm in the 1990s as a response to a NATO solicitation for a Personal Defense Weapon, to which [Read More…]

Four PDW calibers: .22 WMR (Kel-Tec CMR-30 and PMR-30 SMG), .22 SCAMP (Colt SCAMP), 5.7x28mm FN (FN P90), and 4.6x30mm HK (HK MP7).

Modern Personal Defense Weapon Calibers 001: Introduction, and the 5.7x28mm FN

At this point, we’ve talked about 25 different intermediate and full power calibers as part of a series comparing different types of modern small arms ammunition. However, one subject not yet thoroughly covered is rounds for personal defense weapons (PDWs). These [Read More…]

1 Left to right: 4.9x45mm DAG, 4.3x45mm DAG, 4.6x36mm HK/CETME, 4.7x21mm HK early G11, 4.7x33 HK late G11, 4.6x30 HK MP7 Left to right: 7.65x38mm Swiss, 7.5x55 GP.11, 6.45x48mm GP.80, 5.56x45mm SS109 Polymer-cased telescoped ammunition, left to right: .38 cal. Dardick Tround, 5.56x30 Hughes Lockless, 5.56x45 Steyr ACR flechette.

Future Firearms Ammunition Technology 008: Plastic-Cased, Telescoped Ammunition – Lightening the Load, Pt. 4

Previously, we discussed different concepts for lightening the soldier’s load, including aluminum-, composite-cased and caseless ammunition. Today we’re going to look at the weight-reducing concept that many believe is the horse to bet on when it comes to [Read More…]

.264 USA The long-necked Colt 7.62mm round on the left combines the principles of triplex and squeezebore rounds (together called "salvo-squeezebore"). When fired from a modified M60 with a tapered muzzle, it would spit out three 55gr .224" caliber projectiles per shot. In the center is the duplex (not squeezebore) M198 7.62mm round, and on the right is the M80A1 EPR round, for comparison.

Future Firearms Ammunition Technology 007: Squeezebore Ammunition – Celeritas Et Accuratio

Previously, we discussed the benefits of and challenges facing saboted projectile ammunition, including the advantages of decoupling the diameters of the bore and the projectile, and the problems of accuracy during sabot discarding. One concept that could possibly [Read More…]

Multiplex rounds, left to right: .30-06 long neck duplex, .22-06 long neck duplex, .25 Winchester FA T115 short neck duplex, .25 Winchester FA T127 long neck duplex, Colt 7.62 salvo squeezebore triplex, 7.62mm M198 duplex ball, 9.53x76mm Winchester quadruple flechette, .330 Amron Aerojet triple flechette.

Future Firearms Ammunition Technology 006: Multiplex Projectile Ammunition – Two, Three, Four for the Price of One?

After World War II, US Army analysts determined that the effectiveness of the infantryman was not as closely related to their marksmanship discipline as had been previously thought. It seemed that instead, the random environmental circumstances and effects, plus the [Read More…]

Flechette rounds, left to right: XM645 with glass polyester sabot, XM645 with compressed sabot, XM110 with GP sabot, 10gr SPIW flechette and sabot above, XM144 with GP sabot, 10gr SPIW flechette above, .330 Amron Aerojet triple flechette, 9.53x76mmR Winchester quadruple flechette, AAI 5.56x45mm ACR flechette, Steyr 5.56x45mm ACR plastic cased telescoped flechette. Sabot rounds, left to right: XM645 SPIW flechette with compressed disintegrating puller sabot, XM645 SPIW flechette with glass polyester disintegrating puller sabot, 5.77/4.32 Frankford with polymer cup pusher sabot, 5.56x45mm AAI ACR flechette with petal-type puller sabot. Far right is a pulled SPIW sabot and flechette.

Future Firearms Ammunition Technology 003: Sabots – Performance-Enhancing Shoes for Your Bullets

One of the problems of small arms ammunition is that of swept volume. That is, the most ballistically efficient projectiles are the longest and thinnest ones, which cut through the air more easily than squatter, fatter projectiles. Yet, the best projectiles from a [Read More…]

So far, the polymer composite case has only found purchase with low-power specialty ammunition, such as the plastic blank and fired 7.62mm UTM marking round, both on the right. Several commercial composite cased rounds have been tried, including the grey .223 Remington PCA ammunition. In the 1970s, Frankford Arsenal and AAI experimented with composite cased ammunition, represented by the white cased round in the middle. On the left is a standard Korean-made M855 round.

Future Firearms Ammunition Technology 002: Polymer-Cased Composite Ammunition – Lightening the Load, Pt. 2

In the last installment, we talked about the growing need throughout the 20th Century to reduce the weight of the cartridge case, to lighten the burden of the soldier. Experiments in aluminum have thus far proven unsuccessful, but another material is even more [Read More…]

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Modern Historical Intermediate Calibers 020: The 7.62x45mm Czech

After World War II, the nations of the world retired to lick their wounds and rebuild, but their arms engineers also began thinking about the next war. The war have brought forth a storm of new technologies and inventions, and one of the most significant in the field of [Read More…]

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Modern Intermediate Full Power Calibers 019: The Russian 6x49mm Unified

What happens when you take the two concepts of a traditional, full-power rifle and machine gun round, and a small-caliber, high-velocity round, and smash them together? You get one of the most extreme military small arms calibers ever developed, and one of the last [Read More…]

.30 caliber rounds: .30-06 M2 AP, .303 Mk. VII, 7.5x54 Balle C, 7.9x57 sS Patrone, 7.62x54R LPS Ball, 7.62x51 NATO S Patrone (Austria). The 7.92mm Kurzpatrone 43 (middle right) was developed from the larger 7.92mm German infantry cartridge, represented by the 154gr S Patrone (left) and 198gr sS Patrone (middle left). The 7.92x33 Kurz, as it's more commonly called today, is still used by some forces that retain the WWII-era Sturmgewehrs that fire it. The primary producer of ammunition for these weapons today is Prvi Partizan, which made the cartridge on the far right. 5.8x42DBP-10 On the right are two types of 7.62 NATO round, the M80 and M80A1, alongside two of its predecessors. Center left is the .30 T104 ball cartridge using the 1948 T1E1 case. Left is the .300 Savage, which was the starting point for what became the 7.62 NATO. P7152437 The 4.85 British (center) was developed in the UK and competed in the NATO trials that eventually standardized on the Belgian 5.56mm SS109 load (left). Like the similar German 4.9x45mm DAG (right), it is based on the 5.56mm case. The 5.56mm alongside two of its .17 caliber variants. Center, the 4.32x45mm Frankford Arsenal, Right, the German 4.3x45mm DAG. Two .280/30 cartridges, and their immediate ancestors. The .280 concept was inspired by the German 7.92x33 Kurz caliber on the far left, but demands for standardization in testing with the US-developed .30 T65 cartridge (center left) resulted in rounds after 1949 using the same case head as that round. 0810162235bn On the right are the two major iterations of the 6mm SAW, the 45mm steel cased version, and the 50mm aluminum cased version. In the middle is a modified .25 Winchester experimental round used for ballistic testing in the early part of the SAW program. On the far left is 5.56mm M855, which became the eventual chambering for the resulting M249 SAW. The 6x35mm KAC/TSWG flanked by its parent, the .221 Remington Fireball on the left, and the 5.56x45mm on the right, which it is designed to duplicate from shorter barrel lengths. A 5.45x39mm 7N6 cartridge, flanked by two of its predecessors. The 5.6x39mm (left) was developed from an early Soviet ballistic test round using the 7.62x39mm case head, which was designed to duplicate the performance of the early .222 Remington Special (right), later renamed the .223 Remington. 5.56mm (left) alongside some of its competitors. The .25-45 Sharps flanked by the 5.56mm M855 and Mk. 262 rounds. 7.62x40 WT next to its parent, the 5.56mm. On the right are two .300 AAC Blackout rounds, alongside the green-tipped 5.56mm and shorter .221 Remington Fireball that serves as the round's parent case. Two 6.5 Grendel rounds and related cartridges. Left to right: 7.62x39mm, .220 Russian, 6.5 Grendel 123gr SMK, Wolf 100gr FMJ. Three 6.8 SPC cartridges and their parent round. Left to right: .30 Remington, 6.8 SPC 115gr Sierra BTHP, 110gr Hornady OTM, XM68GD 90gr soft point. 7.62x39 and two of its derivatives. Left to right: Commercial FMJ, Yugoslavian M67, 5.6x39mm/.220 Russian, 6.5x38 Grendel. 25_45_animation02 105mm_tank_gun_Rifling BCs
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Review: Newest Edition of Nosler Reloading Guide

In 1946 a man by the name of John Nosler went on a particularly frustrating moose hunt. Nosler had made an accurate killing shot on a moose using his .300 H&H, then watched as the animal failed to go down. Due to the events of that hunt he decided the gun industry [Read More…]

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