A squeeze bore, alternatively taper-bore, cone barrel or conical barrel, is a weapon where the internal barrel diameter progressively decreases towards the muzzle resulting in a reduced final internal diameter. These weapons are used in conjunction with special sub-caliber ammunition where the projectile is fitted with soft-metal flanges which fills out the caliber.[1] As the projectile travels through the squeeze bore the flanges fold inwards, resulting in a reduced caliber round with an increased velocity compared to a traditional full-caliber round.[1]
A squeeze bore utilizes the energy of the propellant to squeeze the diameter of the bullet or shell down, increasing penetration and velocity significantly. This process also meant high chamber pressure and low barrel service life.[2] For example, the service life of a squeeze bore 7.5 cm Pak 41 could be as low as 1000 rounds compared to 5000-7000 rounds for the 7.5 cm Pak 39 (L/48).[3] The diameter of a fired shell could decrease as much as 40% from .50 caliber to .30 caliber (M2 machine gun). Rather than squeezing solid shot, this is accomplished through a hardened penetrator core (tungsten for example) and a softer outer jacket (aluminium alloy) forming flanges or wings. This outer jacket was crushed as the projectile left the barrel.[4][5]
The squeeze bore concept typically was used in anti-tank guns before the widespread use of shaped charges.[4] Later, the perfection of discarding sabot ammo, which is based on the same concept of using a larger caliber barrel to fire a smaller caliber projectile at high-speed, negated the need for the squeeze bore concept.[2]
History and usage
The original patent filed by Hermann Gerlich in 1932[6]
The squeeze bore concept was first patented by German Karl Puff in 1903, even though the general principle was known already in 19th century and used in Armstrong guns. Later, Hermann Gerlich in the 1920s and 1930s experimented with the concept resulting in an experimental 7cm anti-tank rifle with a 1,800 m/s muzzle velocity. This led to the squeeze bore concept sometimes being called the "Gerlich principle."
Between 1939-40, Mauser-Werk AG produced the 2.8 cm sPzB 41 and Krupp (in 1941) produced the 7.5 cm Pak 41. These were eventually discontinued due to the lack of tungsten and manufacturing complexity for the ammunition.[2][7][8]
Other uses of the squeeze bore include the British Littlejohn adaptor, a QF 6-pounder adapter and the M2 machine gun.[5] Squeezing down from 40mm to 30mm, 57mm to 42.6mm, and .50 caliber to .30 caliber respectively. The Littlejohn adapter was used to extend the service life of the QF 2 pounder and was designed by František Janeček whose anglicized name gave the Littlejohn its designation. The QF 6 pounder adapter was never adopted.
Gallery
2.8 cm sPzB 41 squeeze-bore anti-tank gun captured by British forces in Sicily 1943.
4.2 cm Pak 41 light squeeze-bore anti-tank gun in Italy 1943.
^ abcRollof, Yngve. "Artillerimaterielens utvecklingstendenser under senaste decenniet". Tidskrift i Sjöväsendet. Number 7 1953 – via Kungliga Örlogsmannasällskapet.
^ abcMcCollum, Ian (18 February 2017). "Q&A #9: Gas Impingement, Reading List, Squeeze-Bores, and More!". Forgotten Weapons. Youtube. Archived from the original on 2021-12-20. Retrieved 8 July 2018.
^ abMcCollum, Ian (24 April 2018). "Q&A #17: Bullpups, Stocked Pistols, Delayed Blowback, and More!". Forgotten Weapons. Youtube. Archived from the original on 2021-12-20. Retrieved 6 July 2018.
^ ab"Exotic Barrels Part 1: Squeeze Bores | WeaponsMan". weaponsman.com. WeaponsMan. Retrieved 6 July 2018.
^"Squeeze Bore". Shooting with Hobie. 12 January 2011. Retrieved 8 July 2018.
^S, Rusty (20 May 2016). "Mauser's high-tech antitank gun: the 2.8cm sPzB 41 - The Firearm Blog". The Firearm Blog. Retrieved 8 July 2018.
December 27, 2022
squeeze, bore, squeeze, bore, alternatively, taper, bore, cone, barrel, conical, barrel, weapon, where, internal, barrel, diameter, progressively, decreases, towards, muzzle, resulting, reduced, final, internal, diameter, these, weapons, used, conjunction, wit. A squeeze bore alternatively taper bore cone barrel or conical barrel is a weapon where the internal barrel diameter progressively decreases towards the muzzle resulting in a reduced final internal diameter These weapons are used in conjunction with special sub caliber ammunition where the projectile is fitted with soft metal flanges which fills out the caliber 1 As the projectile travels through the squeeze bore the flanges fold inwards resulting in a reduced caliber round with an increased velocity compared to a traditional full caliber round 1 Historical squeeze bore example 7 5 cm Pak 41 squeeze bore gun7 5 cm Pak 41 flange projectiles Left Armor piercing composite non rigid APCNR Right Armor piercing AP Contents 1 Mechanism 2 History and usage 3 Gallery 4 See also 5 ReferencesMechanism Edit Diagram of the squeeze bore concept A squeeze bore utilizes the energy of the propellant to squeeze the diameter of the bullet or shell down increasing penetration and velocity significantly This process also meant high chamber pressure and low barrel service life 2 For example the service life of a squeeze bore 7 5 cm Pak 41 could be as low as 1000 rounds compared to 5000 7000 rounds for the 7 5 cm Pak 39 L 48 3 The diameter of a fired shell could decrease as much as 40 from 50 caliber to 30 caliber M2 machine gun Rather than squeezing solid shot this is accomplished through a hardened penetrator core tungsten for example and a softer outer jacket aluminium alloy forming flanges or wings This outer jacket was crushed as the projectile left the barrel 4 5 The squeeze bore concept typically was used in anti tank guns before the widespread use of shaped charges 4 Later the perfection of discarding sabot ammo which is based on the same concept of using a larger caliber barrel to fire a smaller caliber projectile at high speed negated the need for the squeeze bore concept 2 History and usage Edit The original patent filed by Hermann Gerlich in 1932 6 The squeeze bore concept was first patented by German Karl Puff in 1903 even though the general principle was known already in 19th century and used in Armstrong guns Later Hermann Gerlich in the 1920s and 1930s experimented with the concept resulting in an experimental 7cm anti tank rifle with a 1 800 m s muzzle velocity This led to the squeeze bore concept sometimes being called the Gerlich principle Between 1939 40 Mauser Werk AG produced the 2 8 cm sPzB 41 and Krupp in 1941 produced the 7 5 cm Pak 41 These were eventually discontinued due to the lack of tungsten and manufacturing complexity for the ammunition 2 7 8 Other uses of the squeeze bore include the British Littlejohn adaptor a QF 6 pounder adapter and the M2 machine gun 5 Squeezing down from 40mm to 30mm 57mm to 42 6mm and 50 caliber to 30 caliber respectively The Littlejohn adapter was used to extend the service life of the QF 2 pounder and was designed by Frantisek Janecek whose anglicized name gave the Littlejohn its designation The QF 6 pounder adapter was never adopted Gallery Edit 2 8 cm sPzB 41 squeeze bore anti tank gun captured by British forces in Sicily 1943 4 2 cm Pak 41 light squeeze bore anti tank gun in Italy 1943 A German 10 cm schwere Kanone 18 with an 8 8 cm squeeze bore adapter attached to the muzzle 1 A Mk VII Tetrarch Mk I with a squeeze bore Littlejohn adaptor See also EditChoke firearms Squeeze bore artillery 2 8 cm sPzB 41 4 2 cm Pak 41 7 5 cm Pak 41References Edit a b c Rollof Yngve Artillerimaterielens utvecklingstendenser under senaste decenniet Tidskrift i Sjovasendet Number 7 1953 via Kungliga Orlogsmannasallskapet a b c McCollum Ian 18 February 2017 Q amp A 9 Gas Impingement Reading List Squeeze Bores and More Forgotten Weapons Youtube Archived from the original on 2021 12 20 Retrieved 8 July 2018 Ankerstjerne Christian Anti tank Ammunition Types panzerworld com a b McCollum Ian 24 April 2018 Q amp A 17 Bullpups Stocked Pistols Delayed Blowback and More Forgotten Weapons Youtube Archived from the original on 2021 12 20 Retrieved 6 July 2018 a b Exotic Barrels Part 1 Squeeze Bores WeaponsMan weaponsman com WeaponsMan Retrieved 6 July 2018 Gerlich Hermann Projectile PDF www freepatentsonline com Free Patents Online Retrieved 18 July 2018 Squeeze Bore Shooting with Hobie 12 January 2011 Retrieved 8 July 2018 S Rusty 20 May 2016 Mauser s high tech antitank gun the 2 8cm sPzB 41 The Firearm Blog The Firearm Blog Retrieved 8 July 2018 Retrieved from https en wikipedia org w index php title Squeeze bore amp oldid 1105357429, wikipedia, wiki, book, books, library,
