Spitzer (bullet)



The spitzer bullet, also commonly referred to as a spire point bullet, is primarily a small arms ballistics development of the late 19th and early 20th century, driven by military desire for aerodynamic bullet designs that will give a higher degree of accuracy and kinetic efficiency, especially at extended ranges. To achieve this the projectile must minimize air resistance in flight.

Bullets with a lower drag coefficient (Cd) decelerate less rapidly. A low drag coefficient flattens the projectile's trajectory somewhat at long ranges and also markedly decreases the lateral drift caused by crosswinds. The higher impact velocity of bullets with high ballistic coefficients means they retain more kinetic energy.

The name 'spitzer' is an anglicized form of the German word Spitzgeschoss, literally meaning "pointy bullet".

The development of spitzer bullets made military doctrines possible which expected rifle volleys at area targets at ranges up to 800 to 1000 m. Combined with machine guns equipped with clinometers that could deliver plunging fire or indirect fire at more than 3000 m, spitzer bullets greatly increased the lethality of the battlefield during World War I. After World War I some militaries adopted spitzer bullet designs with improved maximum ranges of 4700 to 5500 m, though plunging fire or indirect fire methods were not commonly used by machine gunners during World War II.

Most spitzer bullets are loaded in intermediate and high-powered rifle cartridges.

France
The spitzer bullet design was first introduced in 1898 as the Balle D by the French Army. The Balle D bullet was designed by captain Desaleux, in order to improve the ballistic performance of the existing French 8×50mmR Lebel service cartridge of 1886.

The original 1886 pattern 8×50mmR Lebel cartridge was an innovative service cartridge design, since it was the first military cartridge to use single-base smokeless, nitrocellulose based, (Poudre B) gunpowder as developed by Paul Vieille in 1884. The original 1886 pattern 8×50mmR Lebel was loaded with a 15.0 g cupro-nickel jacketed lead-cored flat nosed wadcutter-style Balle M bullet designed by lieutenant colonel Nicolas Lebel achieving a muzzle velocity of 628 m/s.

The new 1898 pattern 8×50mmR Lebel cartridge loaded with Desaleux's new lighter 12.8 g Balle D spitzer bullet achieved a muzzle velocity of 700 m/s, providing a somewhat flatter trajectory and a greatly improved maximum effective range. Besides having a pointed nose section the Balle D was also the first military rifle projectile that had a boat tail - a streamlined tapered base - to further minimize air resistance in flight.

Downrange performance
The 1898 pattern 8×50mmR Lebel Balle D spitzer nose profile combined with the boat tail resulted in a ballistic coefficient (G1 BC) of 0.568 to 0.581 (ballistic coefficients are somewhat debatable). Fired at 700 m/s muzzle velocity the Balle D bullet retained supersonic velocity up to and past 800 m (V800 ≈ Mach 1.13) under ICAO Standard Atmosphere conditions at sea level (air density ρ = 1.225 kg/m3). Even by 21st century standards 800 m typical effective supersonic range is regarded as normal for a standard military rifle round.

1886 pattern 8×50mmR Lebel Balle M load

1898 pattern 8×50mmR Lebel Balle D load

The above downrange performance tables show the superior velocity retention of the Balle D compared with its Balle M predecessor Note: The air density ρ used to correlate these tables is unknown.

German Empire
In 1904, after reviewing the French success with the Balle D cartridge, German ordnance authorities decided to revise the Army's M/88 cartridge and its round-nose bullet design. A new Spitzgeschoß aerodynamic bullet, credited to an independent ballistician Arthur Gleinich, was selected. The patent assigned by the US Patent Office to the Deutsche Waffen- und Munitionsfabriken Aktien-Gesellschaft for an Improved Form for Projectiles for Hand-Firearms can be found under. The S Patrone, used a relatively lightweight 9.9 g bullet with a slightly increased diameter of 8.2 mm that had a ballistic coefficient (G1 BC) of approximately 0.321 to 0.337 (ballistic coefficients are somewhat debatable), along with a new double-base (based on nitrocellulose and nitroglycerin) smokeless powder loading, which delivered a greatly improved muzzle velocity of 878 m/s. This cartridge had a maximum range of approximately 3700 m and was adopted by the German Army and Navy as the S Patrone a.k.a. 7.92×57mm Mauser cartridge in 1905. The combination of increased velocity and improved bullet aerodynamics provided a much flatter bullet trajectory, which increased the probability of hitting an individual target at most typical combat distances.

United States
In 1906, United States ordnance authorities arranged to purchase the production license for the Spitzgeschoß bullet design from Gleinich. Now referred to as a 'spitzer' design, the new 9.7 g flat base projectile that had a ballistic coefficient (G1 BC) of approximately 0.405 with a cupro-nickel alloy jacket was incorporated into the M1906 30-06 Springfield cartridge adopted by U.S. armed forces in 1906. The Ball, M1906 rounds had a muzzle velocity of 823 m/s and can be identified by their silver-colored bullets. The cupro-nickel alloy were found to quickly foul the bore.

Russian Empire
In 1908 the Russian Empire adopted a new 7.62×54mmR service round variant loaded with the "L" 9.5 g spitzer bullet that had a ballistic coefficient (G1 BC) of approximately 0.393. The 7.62×54mmR M1908 Type L cartridge had a muzzle velocity of 865 m/s.

United Kingdom of Great Britain and Ireland
In 1910 Britain officially adopted the .303 British Mark VII cartridge variant loaded with a 11.3 g flat base spitzer bullet that had a ballistic coefficient (G1 BC) of approximately 0.467. The .303 British Mark VII cartridge had a muzzle velocity of 744 m/s.

Switzerland


In 1911 Switzerland adopted the 7.5×55mm GP 11 cartridge loaded with a 11.3 g spitzer Full Metal Jacket bullet. Besides a pointed nose the GP11 bullet also had a boat tail. The GP11 projectile had a ballistic coefficient (G1 BC) of 0.505 to 0.514 (ballistic coefficients are somewhat debatable). At 780 m/s muzzle velocity the standard GP 11 ball spitzer bullet retained supersonic velocity up to 800 m (V800 ≈ Mach 1.1) under ICAO Standard Atmosphere conditions at sea level (air density ρ = 1.225 kg/m3).

Kingdom of Spain
In 1913 the ordnance authorities of the Kingdom of Spain issued a redesigned 7×57mm Mauser cartridge (7mm Cartucho para Mauser Tipo S). It was loaded with a 9 g spitzer bullet fired at a muzzle velocity of 850 m/s with 3251 J muzzle energy from a 589 mm long barrel. It had a maximum range of 3700 m.

Sweden
Sweden and Norway loaded their 6.5×55mm m/94 service ammunition with a 10.1 g long round-nosed bullet (B-projectile) fired at a muzzle velocity of 725 m/s up to the early phase of World War II and Norwegian occupation by German in 1940. From 1941 onwards Sweden, which remained neutral during World War II, adopted m/41 service ammunition loaded with a 9.1 g spitzer bullet (D-projectile) with a boat tail fired at a muzzle velocity of 800 m/s. Besides a pointed nose the m/41 D-projectile also had a boat tail.