.400 Corbon
Encyclopedia
The .400 Corbon is an automatic
pistol
cartridge developed by Cor-Bon
in 1997. It was created to mimic the ballistics
of the powerful 10 mm Auto cartridge by means of a .45 ACP case, necked down to .40 caliber
with a 25 degree shoulder.
and the designer of the cartridge, explained his reason for developing the cartridge: "Velocity is the key to making hollowpoint bullets work. The added velocity assures that the hollowpoint will open up even if plugged with material. This reduces the risk of overpenetration and allows the action of the hollowpoint bullet to dump the available energy into the target."
Mr. Pi said because he wanted the .400 Corbon to be easy for handloaders
to make, he based the cartridge on the ubiquitous .45 ACP so that an ample supply of cases were readily available, gave the shoulder a 25 degree angle, and headspaced it on the case shoulder rather than the mouth so that over-all-length is not critical and the bullet can take a tight roll crimp to avoid setback and to get a more efficient powder burn.
The .400 Corbon followed the introduction of the .357 SIG
in 1994, which was essentially a copy of the 9mm Action Express without the rebated rim.
Because of its high velocity for a handgun round, the .400 Corbon offers a flat trajectory, which in turn allows for a greater effective range. Ed Sanow also felt recoil was equivalent to 230 gr hardball in .45 ACP
. In addition, the bottleneck case can function better than a straight case with a wider variety of bullet shapes and sizes and allows the use of fully supported barrels.
Ballistics fall somewhere between the .40 S&W
and the 10 mm Auto
. Unlike the 10 mm which operates at a SAAMI
maximum of 37,500 psi
, the .400 Corbon operates at 29,000 psi (although one source states that the pressure is 26,500 psi), much closer to the SAAMI maximum pressures for .45 ACP (21,000 psi), and .45 ACP +P (23,000 psi). Thus the .400 Corbon does not batter converted model 1911 handguns nearly as harshly as the 10 mm Auto, yet performs comparably with up to 180 gr. bullet weights in handloads.
The .400 Corbon is a versatile cartridge useful for target shooting, practical shooting
competition, self-defense, and handgun hunting
of small and medium game. The loads with the lighter bullets are appropriate for small game. Handloaders have worked up safe loads using 180 gr bullets at 1250 ft/s (381 m/s) making it an adequate round for hunting some medium game at close distances.
For practical shooting competitors, the .400 Corbon makes IPSC
Major Power Factor of 175 and surpasses the IDPA
Enhanced Service Pistol's Power Floor of 125,000 in most loads using a 5" barrel. The .400 Corbon also surpasses the Steel Challenge Shooting Association's stop plate's Power Factor floor of 120 and qualifies for metallic silhouette
Big Bore Competition under IHMSA rules.
According to Ed Sanow, the 135 gr. JHP penetrated 9 inches (228.6 mm) of ordinance gelatin and "equals the predicted stopping power of the 10mm 135 gr JHP loads," and that the 165 gr. JHP "penetrates an ideal 12.3 inches (312.4 mm) of gelatin" and "should be a 92-percent stopper, per the Fuller Index."
s; 155 gr DPX; 135 gr Pow'RBall; 130, 150, and 165 gr tradition JHPs; and 165 gr Performance Match; and is sold by major mail order retailers.
Many shooters, however, handload their own ammunition to save money. Fired .45 ACP cases can be resized and trimmed to handload .400 Corbon cartridges. New brass cases are manufactured by Starline Brass and are readily available directly from them and major mail order retailers such as MidwayUSA. According to Starline Brass, "The primer pocket was changed from large pistol primer to small pistol/rifle primer in 12/00. Test results concluded no adverse affect from switching to small primer pocket. Cor-Bon is now recommending Win. small pistol works best and if using small rifle Remington 7½ works the best."
Lee Precision, Inc. offers a .400 Corbon 3-Die set. Redding Reloading, according to their catalog, offers custom made 3-die sets for the .400 Corbon. Lubricating of the bottleneck case can be avoided when starting with .400 Corbon cases by using a carbide .45 ACP sizing die before using the .400 Corbon sizing die. Using a 5-stage progressive reloading press makes this less of a chore.
Setback of the bullet in the case—which can cause excessive pressure—can be avoided by using a tight roll crimp and, if necessary, Corbin's Hand Cannelure Tool for jacketed bullets. Since the cartridge headspaces on the shoulder rather than the case mouth, a tight crimp will not cause headspace problems.
Information on handloads for the .400 Corbon can be found online, in fact the standard .45 has two SAAMI standards: 21000 psi for standard loads, and 25000 psi for .45+ loads. The top full-power factory 400 Corbon loads just slightly exceed the .45+ standard. It should be noted that most of the starting 400 Corbon loads with a 5" barrel still make the IPSC Major Power Factor, even without stressing the caliber's upper limits.
Corbon said that they gave the 400 Corbon to the market and have no patents on this cartridge whatsoever. Eventually, someone with several thousand dollars may even have SAAMI set a standard for it.
Nearly any .45 ACP pistol can be converted to utilize the .400 Cor-Bon cartridge with only a drop-in replacement barrel
, and sometimes a heavier recoil spring (for 1911s this is usually an 18-20 lb. spring, although a few need a 22-24 lb. spring).
Suitable recoil springs are easily installed when changing barrels and readily available from many gun parts suppliers, including Wolff Gunsprings. There is no need to buy new magazines or guide rods or change extractors.
Because the .400 Corbon shares the same breechface dimensions as the .45 ACP, modern M1911
s can be converted to it without requiring a replacement slide or ejector. Since a .400 Corbon conversion virtually matches the performance of the 10 mm yet does not require purchasing another handgun, some call it the "cheap man's 10 mm." A conversion also retains the versatility of easily converting back to .45 ACP as needed. In this context, Gun & Ammo wrote,
As of July 4, 2008, the following companies offered .400 Corbon conversion barrels: Clark Custom Guns (drop-in standard and compensated barrels for 1911s); EFK Fire Dragon (1911s, Glocks
, Sig P220
, HK USP, and the Springfield XD); Fusion Firearms (1911s); Jarvis Inc. (1911s) (Glock); King's Gun Works (1911s); and Les Baer (1911s in National Match grade in 5" and 6" inch barrel lengths). Roto 4M (1911 series barrels in 4-1/4" (Commander), 5" and 6" lengths (Government)). Bar-Sto no longer offers them. lone wolf distributors also offer a drop-in conversion barrel in 400 corbon for the glock 21.
Semi-automatic firearm
A semi-automatic, or self-loading firearm is a weapon which performs all steps necessary to prepare the weapon to fire again after firing—assuming cartridges remain in the weapon's feed device or magazine...
pistol
Pistol
When distinguished as a subset of handguns, a pistol is a handgun with a chamber that is integral with the barrel, as opposed to a revolver, wherein the chamber is separate from the barrel as a revolving cylinder. Typically, pistols have an effective range of about 100 feet.-History:The pistol...
cartridge developed by Cor-Bon
Cor-Bon
Cor-Bon is a brand of small arms ammunition produced by Dakota Ammo Incorporated. The company, based in Sturgis, South Dakota, was founded in 1982 by Peter Pi....
in 1997. It was created to mimic the ballistics
Ballistics
Ballistics is the science of mechanics that deals with the flight, behavior, and effects of projectiles, especially bullets, gravity bombs, rockets, or the like; the science or art of designing and accelerating projectiles so as to achieve a desired performance.A ballistic body is a body which is...
of the powerful 10 mm Auto cartridge by means of a .45 ACP case, necked down to .40 caliber
Caliber
In guns including firearms, caliber or calibre is the approximate internal diameter of the barrel in relation to the diameter of the projectile used in it....
with a 25 degree shoulder.
History and Design
Peter Pi, founder of Cor-BonCor-Bon
Cor-Bon is a brand of small arms ammunition produced by Dakota Ammo Incorporated. The company, based in Sturgis, South Dakota, was founded in 1982 by Peter Pi....
and the designer of the cartridge, explained his reason for developing the cartridge: "Velocity is the key to making hollowpoint bullets work. The added velocity assures that the hollowpoint will open up even if plugged with material. This reduces the risk of overpenetration and allows the action of the hollowpoint bullet to dump the available energy into the target."
Mr. Pi said because he wanted the .400 Corbon to be easy for handloaders
Handloading
Handloading or reloading is the process of loading firearm cartridges or shotgun shells by assembling the individual components , rather than purchasing completely assembled, factory-loaded cartridges...
to make, he based the cartridge on the ubiquitous .45 ACP so that an ample supply of cases were readily available, gave the shoulder a 25 degree angle, and headspaced it on the case shoulder rather than the mouth so that over-all-length is not critical and the bullet can take a tight roll crimp to avoid setback and to get a more efficient powder burn.
The .400 Corbon followed the introduction of the .357 SIG
.357 SIG
The .357 SIG pistol cartridge is the product of Swiss-German firearms manufacturer SIG-Sauer, in cooperation with the American ammunition manufacturer Federal Cartridge. While it is based on a .40 S&W case necked down to accept bullets, the .357 SIG brass is slightly longer...
in 1994, which was essentially a copy of the 9mm Action Express without the rebated rim.
Performance
According to Guns & Ammo magazine,
Performance is on a par with the 10 mm, yet pressures are much milder. Factory ammo is loaded to +P .45 levels, but the lighter bullet weights make recoil comparable to .45 hardball loads. Felt recoil is a little sharper but still very controllable.
Because of its high velocity for a handgun round, the .400 Corbon offers a flat trajectory, which in turn allows for a greater effective range. Ed Sanow also felt recoil was equivalent to 230 gr hardball in .45 ACP
.45 ACP
The .45 ACP , also known as the .45 Auto by C.I.P., is a cartridge designed by John Browning in 1904, for use in his prototype Colt semi-automatic .45 pistol and eventually the M1911 pistol adopted by the United States Army in 1911.-Design and history:The U.S...
. In addition, the bottleneck case can function better than a straight case with a wider variety of bullet shapes and sizes and allows the use of fully supported barrels.
Ballistics fall somewhere between the .40 S&W
.40 S&W
The .40 S&W is a rimless pistol cartridge developed jointly by major American firearms manufacturers Winchester and Smith & Wesson. The .40 S&W was developed from the ground up as a law enforcement cartridge designed to duplicate performance of the FBI's reduced velocity 10mm cartridge which could...
and the 10 mm Auto
10 mm Auto
The 10mm Auto is a semi-automatic pistol cartridge developed by Jeff Cooper and introduced in 1983 for the Bren Ten pistol. It was initially produced by ammunitions manufacturer FFV Norma AB of Åmotfors, Sweden.Although it was selected by the F.B.I. for use in the field following the 1986 F.B.I...
. Unlike the 10 mm which operates at a SAAMI
Saami
Saami or SAAMI can stand for:*Sami people*Sami languages*Sporting Arms and Ammunition Manufacturers' Institute...
maximum of 37,500 psi
Pounds per square inch
The pound per square inch or, more accurately, pound-force per square inch is a unit of pressure or of stress based on avoirdupois units...
, the .400 Corbon operates at 29,000 psi (although one source states that the pressure is 26,500 psi), much closer to the SAAMI maximum pressures for .45 ACP (21,000 psi), and .45 ACP +P (23,000 psi). Thus the .400 Corbon does not batter converted model 1911 handguns nearly as harshly as the 10 mm Auto, yet performs comparably with up to 180 gr. bullet weights in handloads.
The .400 Corbon is a versatile cartridge useful for target shooting, practical shooting
Practical shooting
Practical shooting is a sport which challenges an individual's ability to shoot rapidly and accurately with a full-power handgun, rifle, or shotgun. To do this, shooters take on obstacle-laden shooting courses called stages, some requiring many shots to complete, and others just a few...
competition, self-defense, and handgun hunting
Handgun hunting
Handgun hunting is primarily done with specialized handguns that have long barrels and are often set up with scopes .Even the largest animals, such as elephants, can be killed with modern hunting handguns, although most handgun hunters only use handguns when hunting medium-sized game like deer and...
of small and medium game. The loads with the lighter bullets are appropriate for small game. Handloaders have worked up safe loads using 180 gr bullets at 1250 ft/s (381 m/s) making it an adequate round for hunting some medium game at close distances.
For practical shooting competitors, the .400 Corbon makes IPSC
International Practical Shooting Confederation
The International Practical Shooting Confederation is a shooting sport based on the concept of practical shooting. Accuracy, power and speed are all required to achieve a maximum score.-Founding and organization:...
Major Power Factor of 175 and surpasses the IDPA
International Defensive Pistol Association
The International Defensive Pistol Association , founded in 1996, is an organization based in Berryville, Arkansas, USA that promotes defensive pistol shooting as a sport, using equipment including full-charge service ammunition to solve simulated "real world" self-defense scenarios...
Enhanced Service Pistol's Power Floor of 125,000 in most loads using a 5" barrel. The .400 Corbon also surpasses the Steel Challenge Shooting Association's stop plate's Power Factor floor of 120 and qualifies for metallic silhouette
Metallic silhouette
Metallic silhouette shooting is a group of target shooting disciplines that involves shooting at metal cutouts representing game animals at varying distances. Metallic silhouette shooting can be done with airguns, black powder firearms, modern handguns, or modern rifles...
Big Bore Competition under IHMSA rules.
According to Ed Sanow, the 135 gr. JHP penetrated 9 inches (228.6 mm) of ordinance gelatin and "equals the predicted stopping power of the 10mm 135 gr JHP loads," and that the 165 gr. JHP "penetrates an ideal 12.3 inches (312.4 mm) of gelatin" and "should be a 92-percent stopper, per the Fuller Index."
Ammunition and handloading
Factory made ammunition is available from Cor-Bon in a variety of bullet weights and types: 115 gr Glaser Safety SlugGlaser Safety Slug
Glaser Safety Slug is a frangible bullet made by Glaser Safety Slug, Inc., a small American ammunition company based in Sturgis, South Dakota . The company was founded in 1975 by Armin Glaser the same year as the Glaser Safety Slug was developed by Jack Canon.-History:The original round was a...
s; 155 gr DPX; 135 gr Pow'RBall; 130, 150, and 165 gr tradition JHPs; and 165 gr Performance Match; and is sold by major mail order retailers.
Many shooters, however, handload their own ammunition to save money. Fired .45 ACP cases can be resized and trimmed to handload .400 Corbon cartridges. New brass cases are manufactured by Starline Brass and are readily available directly from them and major mail order retailers such as MidwayUSA. According to Starline Brass, "The primer pocket was changed from large pistol primer to small pistol/rifle primer in 12/00. Test results concluded no adverse affect from switching to small primer pocket. Cor-Bon is now recommending Win. small pistol works best and if using small rifle Remington 7½ works the best."
Lee Precision, Inc. offers a .400 Corbon 3-Die set. Redding Reloading, according to their catalog, offers custom made 3-die sets for the .400 Corbon. Lubricating of the bottleneck case can be avoided when starting with .400 Corbon cases by using a carbide .45 ACP sizing die before using the .400 Corbon sizing die. Using a 5-stage progressive reloading press makes this less of a chore.
Setback of the bullet in the case—which can cause excessive pressure—can be avoided by using a tight roll crimp and, if necessary, Corbin's Hand Cannelure Tool for jacketed bullets. Since the cartridge headspaces on the shoulder rather than the case mouth, a tight crimp will not cause headspace problems.
Information on handloads for the .400 Corbon can be found online, in fact the standard .45 has two SAAMI standards: 21000 psi for standard loads, and 25000 psi for .45+ loads. The top full-power factory 400 Corbon loads just slightly exceed the .45+ standard. It should be noted that most of the starting 400 Corbon loads with a 5" barrel still make the IPSC Major Power Factor, even without stressing the caliber's upper limits.
Corbon said that they gave the 400 Corbon to the market and have no patents on this cartridge whatsoever. Eventually, someone with several thousand dollars may even have SAAMI set a standard for it.
Handguns and conversions
Les Baer offers both his Baer 1911 Premier II 5" and Premier II Super-Tac pistols either in .400 Corbon or as a .400 Corbon & .45 ACP dual caliber combination.Nearly any .45 ACP pistol can be converted to utilize the .400 Cor-Bon cartridge with only a drop-in replacement barrel
Gun barrel
A gun barrel is the tube, usually metal, through which a controlled explosion or rapid expansion of gases are released in order to propel a projectile out of the end at a high velocity....
, and sometimes a heavier recoil spring (for 1911s this is usually an 18-20 lb. spring, although a few need a 22-24 lb. spring).
Suitable recoil springs are easily installed when changing barrels and readily available from many gun parts suppliers, including Wolff Gunsprings. There is no need to buy new magazines or guide rods or change extractors.
Because the .400 Corbon shares the same breechface dimensions as the .45 ACP, modern M1911
M1911
The M1911 is a single-action, semi-automatic, magazine-fed, and recoil-operated handgun chambered for the .45 ACP cartridge. John M. Browning designed the firearm which was the standard-issue side arm for the United States armed forces from 1911 to 1985. The M1911 is still carried by some U.S....
s can be converted to it without requiring a replacement slide or ejector. Since a .400 Corbon conversion virtually matches the performance of the 10 mm yet does not require purchasing another handgun, some call it the "cheap man's 10 mm." A conversion also retains the versatility of easily converting back to .45 ACP as needed. In this context, Gun & Ammo wrote,
The .400 Cor-Bon is one of the more useful of the current crop of .45 ACP offspring. There are faster rounds, but the .400 Cor-Bon is simply easy to get along with. You don't need extra-heavy springs or tricked-out guns for this round -- just drop a .400 Cor-Bon barrel in your favorite .45 and you are good to go.
As of July 4, 2008, the following companies offered .400 Corbon conversion barrels: Clark Custom Guns (drop-in standard and compensated barrels for 1911s); EFK Fire Dragon (1911s, Glocks
Glock pistol
The Glock pistol, sometimes referred to by the manufacturer as Glock "Safe Action" Pistol, is a series of semi-automatic pistols designed and produced by Glock Ges.m.b.H., located in Deutsch-Wagram, Austria. The company's founder, engineer Gaston Glock, had no experience with firearm design or...
, Sig P220
SIG P220
The SIG P220 is a semi-automatic pistol designed in Switzerland by Swiss Arms AG . It is manufactured in Eckernförde, Germany, by J.P. Sauer und Sohn GmbH. It uses the Browning linkless cam short recoil action of self-loading with a double action trigger mechanism...
, HK USP, and the Springfield XD); Fusion Firearms (1911s); Jarvis Inc. (1911s) (Glock); King's Gun Works (1911s); and Les Baer (1911s in National Match grade in 5" and 6" inch barrel lengths). Roto 4M (1911 series barrels in 4-1/4" (Commander), 5" and 6" lengths (Government)). Bar-Sto no longer offers them. lone wolf distributors also offer a drop-in conversion barrel in 400 corbon for the glock 21.