.400 Corbon

Infobox Firearm Cartridge
name= .400 Corbon


caption=
origin= flagcountry|United States
type= Pistol
service=
used_by=
wars=
designer= Peter Pi
design_date=1997
manufacturer=Cor-Bon
production_date=
number=
variants=
is_SI_specs=
parent=.45 ACP
case_type=Rimless, bottleneck
bullet=.401
neck=.423
shoulder=.469
base=.470
rim_dia=.471
rim_thick=.050
case_length=.898
length=1.20
rifling=16
primer=small pistol/rifle
is_SI_ballistics=
bw1=135
btype1=JHP
vel1=1400
en1=588
bw2=150
btype2=JHP
vel2=1310
en2=572
bw3=165
btype3=JHP
vel3=1250
en3=573
bw4=
btype4=
vel4=
en4=
bw5=
btype5=
vel5=
en5=
test_barrel_length=
balsrc= Corbon [http://www.dakotaammo.net/products/corbon/caliberloaddata.htm .400 Corbon load data from Corbon] ] The .400 Corbon is an automatic pistol cartridge developed by Cor-Bon in 1997. [http://www.dakotaammo.net/custserv/catalog.pdf Corbon Catalog p.2] ] It was created to mimic the ballistics of the powerful 10mm Auto cartridge in a .45 ACP form factor.It is essentially a .45 ACP case, necked down to .40 caliber with a 25 degree shoulder.

History and Design

Peter Pi, founder of Cor-Bon 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." [http://www.bren-ten.com/website/id7.html "The 10mm Auto Cartridge", "Part 5: 10mm "Offspring" and "Stepchildren," quoting an expired Cor-bon webpage, retrieved 5 July 2008] ]

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. [http://findarticles.com/p/articles/mi_m0BQY/is_6_45/ai_55605616 "GUNS Magazine", "Storm from the East," by Clair Rees (1999), retrieved from Bnet on 5 July 2008] ]

The .400 Corbon followed the introduction of the .357 SIG in 1994, which was the first new bottleneck commercial handgun cartridge since the early 1960s.Fact|date=October 2008

Performance

According to "Guns & Ammo" magazine,

Performance is on a par with the 10mm, 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. [http://www.handgunsmag.com/ammunition/1911_hot_rods/index1.html "Guns & Ammo", "1911 Hot Rods"] ]

Because of its relatively high velocity for a handgun round, the .400 Corbon offers a very flat trajectory, which in turn allows the firearms chambered for it more effective range. Ed Sanow also felt recoil was equivalent to 230 gr hardball in .45 ACP. [http://nordicg3k.tripod.com//sitebuildercontent/sitebuilderpictures/handguns_aug96-04.jpg"Handguns", "400 Cor-Bon: Sizzling New Auto Pistol Cartridge," by Ed Sanow, p. 57, August 1996] ] 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 10mm 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), [http://nordicg3k.tripod.com//sitebuildercontent/sitebuilderpictures/handguns_aug96-02.jpg"Handguns", "400 Cor-Bon: Sizzling New Auto Pistol Cartridge," by Ed Sanow, p. 55, August 1996] ] [http://www.recguns.com/Sources/IVG12.html "400 CorBon," by Peter Jordan] ] much closer to the SAAMI maximum pressures for .45 ACP (21,000 psi), and .45 ACP +P (23,000 psi). [ [http://www.lasc.us/SAAMIMaxPressure.htm Maximum Chamber Pressure SAAMI Specs] ] Thus the .400 Corbon does not batter converted model 1911 handguns nearly as harshly as the 10mm 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 the 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 fps making it an adequate round for hunting some medium game at close distances. [ [http://bananafufu.blogspot.com/2008/04/400-corbon-vs-10mm-conclusions.html "180gr on 400 Corbon and 10mm", April 10, 2008] ]

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. [ [http://www.ipsc.org/ IPSC Handgun Competiton Rules, January 2006 Ed., .pdf, retrieved 4 July 2008] ] [ [http://www.idpa.com/ IDPA Rule Book 2005, retrieved .pdf on 4 July 2008] ] 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. [ [http://steelchallenge.com/scsa-clubs/scsa-rules/ SCSA Match Rules and Conditions] ] [ [http://www.ihmsa.org/2007%20Rules%20Revised_files/2007%20Rules%20Revised.htm IHMSA Official Rules, retrieved 4 July 2008] ]

According to Ed Sanow, the 135 gr. JHP penetrated 9 inches of ordinance gelatin and "equals the predicted stopping power of the 10mm 135 grain JHP loads," and that the 165 gr. JHP "penetrates an ideal 12.3 inches 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 Slugs; 155 gr DPX; 135 gr Pow'RBall; 130, 150, and 165 gr tradition JHPs; and 165 gr Performance Match; [ [http://www.dakotaammo.net/index.html Dakota Ammo, retrieved 4 July 2008] ] and is sold by major mail order retailers. [ [http://www.cheaperthandirt.com/ammowizard.asp CheaperThanDirt.com, retrieved 4 July 2008] ] [ [http://www.midwayusa.com/browse/BrowseCategories.aspx?TabID=3&Categoryid=691&categorystring=653***&utm_source=handgunammoleft&utm_medium=homepage63008 MidwayUSA, retrieved 4 July 2008] ]

Many shooters, however, handload their own ammunition to save money. Fired .45 ACP cases can be resized and trimmed to handload .400 Corbon cartridges. [http://bananafufu.blogspot.com/2008/01/400-corbon-cheap-mans-10mm.html "400 Corbon: A Cheap Man's 10mm," 13 Jan 2008, retrieved 4 July 2008] ] New brass cases are manufactured by Starline Brass and are readily available directly from them and major mail order retailers such as MidwayUSA. [ [http://www.starlinebrass.com/ Starline Brass] ] [ [http://www.midwayusa.com/ 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 7 1/2 works the best." [ [http://www.starlinebrass.com/ Starline Product Information & Descriptions, 400 Cor-Bon] ]

Lee Precision, Inc. offers a .400 Corbon 3-Die set. [ [http://www.leeprecision.com/cgi/catalog/cart.cgi?1215235165.3011=90430 Lee Precision, 3-Die Steel, 400 Corbon, retrieved 4 July 2008] ] Redding Reloading, according to their catalog, offers custom made 3-die sets for the .400 Corbon. [ [http://www.reddingreloading.com/pages/onlinecat.html Redding Reloading, Online Catalog, Die Caliber Reference Chart, retrieved 18 September 2008] ] 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. [ [http://www.corbins.com/hct-1.htm Corbin Hand Cannelure Tool] ] 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. [ [http://www.handloads.org/loaddata/default.asp?Caliber=400%20Corbon&Weight=All&type=Handgun&Order=Powder&Source= Handloads.com, 400 Corbon Load Data, retrieved 18 September 2008] ] [ [http://www.recguns.com/Sources/IVG12.html Rec.guns.com, IV. Comparative Firearm Information, G. Caliber Issues, 12. 400 CorBon, retrieved 18 September 2008] ]

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. [ [http://www.lesbaer.com/duty.html Les Baer, retrieved 4 July 2008] ]

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 18-20lb. spring, although a few need a 22-24lb. spring). cite book
last = Barnes
first = Frank C.
editor = Skinner, Stan
title = Cartridges of the World
edition = 11th Edition
origyear = 1965
year = 2006
publisher = Gun Digest Books
location = Iola, WI, USA
pages = 263,285
isbn = 0-89689-297-2] [ [http://www.dakotaammo.net/faq.htm "Dakota Ammo FAQs," retrieved 5 July 2008] ] Suitable recoil springs are easily installed when changing barrels and readily available from many gun parts suppliers, including Wolff Gunsprings. [ [http://www.gunsprings.com/ Wolff Gunsprings] ] There is no need to buy new magazines or guide rods or change extractors.

Because the .400 Corbon operates at much lower pressures than the 10mm, modern 1911s can be converted to it without suffering the cracked frames and slide rails that plagued the 10mm Colt Delta Elite. [ [http://en.wikipedia.org/wiki/Colt_Delta_Elite#Design Colt Delta Elite, Design, retrieved 4 July 2008] ] [ [http://en.wikipedia.org/wiki/10mm_Auto#History 10mm Auto History, retrieved 4 July 2008] ] Since a .400 Corbon conversion virtually matches the performance of the 10mm yet does not require purchasing another handgun, some call it the "cheap man's 10mm." Plus, you retain the versatility of easily switching back to .45 ACP whenever you desire.

As "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 4 July 2008, the following companies offer .400 Corbon conversion barrels: Clark Custom Guns offers drop-in standard and compensated barrels for 1911s; [ [http://www.clarkcustomguns.com/1911dtl.htm Clark Custom Guns, Parts -- 130 and 165 Series, retrieved 4 July 2008] ] EFK Fire Dragon offers them for 1911s, Glocks, Sig 200, HK USP, and the Springfield XD; [ [https://www.efkfiredragon.com/categories.php?cat=1 EFK Fire Dragon] ] Jarvis Inc. offers them for 1911s; [ [http://www.jarvis-custom.com/Products/tabid/53/ctl/ProductDetail/productId/49/mid/388/Default.aspx Jarvis Inc. 1911 Pistol Barrels, retrieved 4 July 2008] ] King's Gun Works also offers them for 1911s; [ [http://www.kingsgunworks.com/newcatalog/page10.html King's Gun Work's catalog, retrieved 4 July 2008] ] and Les Baer offers them for 1911s in National Match grade in 5" and 6" inch barrel lengths. [ [http://www.lesbaer.com/parts3.html Les Baer High Performance Components and Parts, retrieved 4 July 2008] ] Bar-Sto no longer offers them. [ [http://www.barsto.com/contact.cfm Bar-Sto Precision Machine, retrieved 4 July 2008] ]

ee also

* List of handgun cartridges

References

External links

* [http://www.reloadammo.com/400corbn.htm Reloading the 400 Corbon]
* [http://www.accuratepowder.com/data/PerCaliber2Guide/Handgun/Standarddata/40Cal(10mm)/400%20Corbon%20pages%20119%20and%20120%20Handgun.pdf .400 Corbon data from Accurate Powder]
* [http://www.handloads.org/loaddata/default.asp?Caliber=400%20Corbon&Weight=All&type=Handgun&Order=Powder&Source= 400 Corbon Load Data -- Handloads.com]