Classifications

• • C—CHEMISTRY; METALLURGY
  • C06—EXPLOSIVES; MATCHES
  • C06B—EXPLOSIVES OR THERMIC COMPOSITIONS; MANUFACTURE THEREOF; USE OF SINGLE SUBSTANCES AS EXPLOSIVES
  • C06B23/00—Compositions characterised by non-explosive or non-thermic constituents
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F42—AMMUNITION; BLASTING
  • F42B—EXPLOSIVE CHARGES, e.g. FOR BLASTING, FIREWORKS, AMMUNITION
  • F42B5/00—Cartridge ammunition, e.g. separately-loaded propellant charges
  • F42B5/02—Cartridges, i.e. cases with charge and missile
  • F42B5/24—Cartridges, i.e. cases with charge and missile for cleaning; for cooling; for lubricating ; for wear reducing
• • C—CHEMISTRY; METALLURGY
  • C06—EXPLOSIVES; MATCHES
  • C06B—EXPLOSIVES OR THERMIC COMPOSITIONS; MANUFACTURE THEREOF; USE OF SINGLE SUBSTANCES AS EXPLOSIVES
  • C06B23/00—Compositions characterised by non-explosive or non-thermic constituents
  • C06B23/04—Compositions characterised by non-explosive or non-thermic constituents for cooling the explosion gases including antifouling and flash suppressing agents

Definitions

• This disclosure relates to an addition to every kind of propellant effective for removing copper deposits from the inside surfaces of gun barrels. More particularly, a composite addition that has a pulverized decoppering agent mixed into the propellant.
• Most guns have a barrel with a rifled internal bore that imparts a stabilizing spin on an expelled projectile.
• the internal bore may be coated with a hard facing material, such as chromium, to minimize erosive wear, and thus increasing the number of projectiles that may be fired from the gun.
• the typical large caliber projectile has a diameter slightly less than the diameter of the internal bore.
• One or more obturator, or rotating, bands gird the circumference of the projectile. At the bands, the diameter of the projectile is slightly larger than the internal diameter of the gun barrel.
• the rotating band is engraved by the rifling, contacting the rifling throughout the length of the tube imparting the projectile with a stabilizing spin.
• Projectiles for rifles and pistols normally do not have a rotating band, but they very often have a jacket made out of tombac, which is engraved by the rifling.
• the gun barrel is manufactured from a material such as steel and sometimes coated with a hard material such as chromium facing.
• the gun barrel is harder than the rotating band of jacket, which is typically copper or copper alloy.
• This copper deposition referred to as “copper fouling”, can affect the ballistics of the projectile and major fouling can prevent the projectile from being inserted and seated, positioned in the barrel prior to firing, properly.
• Copper fouling is currently a major problem for large artillery weapons, such as 155-millimeter howitzers, and is also noted in small and medium caliber cannons, such as 20-millimeter canons. It has become a bigger problem in rifles today because of the use of lead-free primers. Before, the primer contained a small amount of lead, which worked as a decoppering agent. The current solution to copper fouling is including a decoppering agent into the propellant. The decoppering agent removes the copper without damaging the gun barrel or the rifling.
• a common decoppering agent is a sheet of lead foil deposited between the propellant and the projectile. On ignition of the propellant charge, the lead is vaporized and diffuses into the copper. The resultant alloy is brittle and easily shattered. The combination of the heat generated by the burning propellant and the mechanical movement of the propellant gases separates the brittle lead/copper alloy from the surface of the barrel. The fractured debris is swept from the muzzle of the gun with the propellant gases.
• lead foil is effective as a decoppering agent is that the heat generated by the burning propellant melts the lead foil. Liquid lead contacts the copper deposition and dissolves the copper, and the copper bearing the lead solution is then expelled as a liquid from the muzzle with the propellant gases.
• the decoppering agent consists essentially of a lead-free pulverized additive mixed together with the other propellant compounds.
• a mixture of tin and bismuth is a very good decoppering agent.
• the ratio between tin and bismuth is between 10-62% Sn and 90-38% Bi, and especially in the ratio 42% SN/58% Bi, the melting point for this combination is 138 degrees C. This melting point is much lower than each of the components.
• the decoppering agent can contain all kinds of suitable tin and bismuth compounds.
• Some suitable compounds are selected from the group consisting of metallic bismuth, bismuth alloys, bismuth compounds, metallic tin, tin alloys and tin compounds.
• the bismuth and tin either vaporizes or liquifies when the propellant is ignited and either embrittles or dissolves the copper deposits facilitating removal.
• this disclosure makes possible an essentially lead free decoppering agent that is included in the propellant.
• the decoppering agent is a part of the propellant and is distributed homogenously throughout the propellant.
• the decoppering agent is distributed to the barrel and trough the barrel with the propellant gases. Including the decoppering agent in the propellant also means that the powder gases always contain the same amount of decoppering agent.
• the biggest advantage is that the decoppering agent always is there, thus making the loading easier and cheaper. No need exists for extra containers with especially made substances for decoppering.

Landscapes

• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• Manufacture And Refinement Of Metals (AREA)
• Cleaning And De-Greasing Of Metallic Materials By Chemical Methods (AREA)
• Medicines Containing Material From Animals Or Micro-Organisms (AREA)
• Powder Metallurgy (AREA)
• Solid-Sorbent Or Filter-Aiding Compositions (AREA)
• Lubricants (AREA)
• Non-Silver Salt Photosensitive Materials And Non-Silver Salt Photography (AREA)
• Paints Or Removers (AREA)
• Pharmaceuticals Containing Other Organic And Inorganic Compounds (AREA)
• Medicines Containing Plant Substances (AREA)
• Manufacture Of Metal Powder And Suspensions Thereof (AREA)

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Applications Claiming Priority (4)

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Family Applications (1)

Country Status (17)

Cited By (2)

Families Citing this family (5)

Citations (1)

Family Cites Families (3)

• 2002
  • 2002-02-08 SE SE0200366A patent/SE523997C2/sv not_active IP Right Cessation
• 2003
  • 2003-01-13 RO ROA200400705A patent/RO122058B1/ro unknown
  • 2003-01-13 EA EA200401051A patent/EA006416B1/ru not_active IP Right Cessation
  • 2003-01-13 HU HU0402655A patent/HU228870B1/hu not_active IP Right Cessation
  • 2003-01-13 CA CA002475497A patent/CA2475497A1/en not_active Abandoned
  • 2003-01-13 DE DE60331890T patent/DE60331890D1/de not_active Expired - Lifetime
  • 2003-01-13 KR KR1020047012179A patent/KR100950907B1/ko not_active IP Right Cessation
  • 2003-01-13 JP JP2003565922A patent/JP4298512B2/ja not_active Expired - Fee Related
  • 2003-01-13 AU AU2003201797A patent/AU2003201797A1/en not_active Abandoned
  • 2003-01-13 AT AT03700650T patent/ATE462680T1/de not_active IP Right Cessation
  • 2003-01-13 EP EP03700650A patent/EP1472199B1/de not_active Expired - Lifetime
  • 2003-01-13 CN CNB038033666A patent/CN1290803C/zh not_active Expired - Fee Related
  • 2003-01-13 WO PCT/SE2003/000028 patent/WO2003066544A1/en active Application Filing
  • 2003-01-13 BR BRPI0307511-7A patent/BR0307511B1/pt not_active IP Right Cessation
• 2004
  • 2004-01-01 ZA ZA200406262A patent/ZA200406262B/xx unknown
  • 2004-08-05 IL IL163376A patent/IL163376A/en not_active IP Right Cessation
  • 2004-08-09 US US10/913,426 patent/US20050115452A1/en not_active Abandoned

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