.40 Super

The .40 Super is an automatic pistol cartridge developed in 1996 and introduced to the market by Triton Cartridge. The cartridge was co-developed by Fernando Coelho and Tom Burczynski.

History and design
In 1994 Triton Cartridge, an ammunition company based in upstate NY, released a cartridge called the .45 Super. Essentially, the .45 Super is based on a .451 Detonics case trimmed to .45 ACP length. Pioneered by writers Dean Grennell and the late Tom Ferguson, the .45 Super raised the performance level for .45 ACP-chambered autos beyond that of the .45 ACP+P and even the 10mm.



With the availability of the strong .45 Super cartridge case, in January 1996 Fernando Coelho (president and founder of Triton Cartridge) and Tom Burczynski (inventor of Hydra-Shok, Starfire and Quik-Shok bullets) began work on a new, more radical cartridge. Based on a .45 Super necked down to .40 caliber, the new cartridge began to take shape.

Actually, necking a .45 ACP to .40 caliber was nothing new. Before the public debut of the .40 S&W, Charles Petty, a well-known and respected writer, had already ventured into the bottleneck arena. His cartridge, called the “10mm Centaur”, was based on a .45 ACP case necked to .40 caliber using 10mm dies. Prior to that, Dean Grennell took .451 Detonics cases and necked them down to 9mm, calling it the .38/45 Hard Head.

Charles Petty was a major contributor in the initial load development for Triton’s new cartridge. During that time, Triton began closely examining the specific attributes of the cartridge (feed reliability, case strength, down-range ballistic performance, etc.). In order to maximize the performance potential and reliability of the new cartridge, it was decided to lengthen the cartridge case from .45 ACP (.898”) to 10mm (.992”) length. By trimming .45 Winchester Magnum brass to 10mm case length and necking them to .40 caliber, the .40 Super began to take final shape.



Working closely with Starline Brass Company, more testing was conducted on the cartridge case. These tests led to further improvements. A small primer pocket replaced the large primer pocket. This allowed the use of small pistol magnum or small rifle primers and helped control primer flow. The final improvement came with the increased thickness of the cartridge case wall from the web area up to the beginning of the shoulder. This created a cartridge case stronger than the .45 Winchester Magnum cartridge case.

The .40 Super cartridge case was designed for a balance of strength and powder capacity. To maximize bullet pull and overall feeding characteristics, the case has a neck length of .175”. The shoulder angle is an optimum 25 degrees. The neck yields more precise bullet alignment than can be achieved using a cartridge with a shorter neck. This translates to increased accuracy. The pressure limit for factory .40 Super ammunition from Triton was 37,000 PSI, well below the strength limits of the cartridge case.

The .40 Super drove a 135 grain bullet to 1,800 feet per second while generating less chamber pressure than the Winchester 9 X 23. With a 200 grain bullet the .40 Super delivers more foot/pounds of energy at 100 yards than the .45 ACP does at the muzzle. From a sheer power standpoint, the .40 Super rivals the energy generated by the .44 Magnum.

Trivia: The original plan was to market the .40 Super as the 40 SIG, the big brother to the 357 SIG. The cartridge was introduced in 1996 to Michael Bussard, the Assistant to the President of SigArms, and he was interested in the cartridge for use in the P220 Pistol.

Initial prototype .40 Super brass actually had a headstamp that read, “.45 Colt” with the second batch of prototype cases stamped "45 WinMag". Starline Brass, the manufacturer of the .40 Super cartridge case, used .45 Colt forming dies and later the 45 Win Mag dies. Ultimately the headstamp was updated to read, “Triton .40 Super”.



Ammunition and handloading
From a reloader standpoint, there was tremendous versatility in the .40 Super. Bullet weights on the market included: 125, 135, 150, 155, 165, 170, 180, 190, 200 and 220 grains. Loads were developed with a dozen powders. Small Pistol Magnum or Small Rifle primers could be utilized. Brass was available from both Triton and Starline Brass Company.

Many semi-autos can accommodate the .40 Super. Semi-autos already chambered for the .45 ACP cartridge are the easiest to convert. This is accomplished by simply swapping out the .45 ACP barrel with the .40 Super barrel and upgrading the recoil spring system with a heavy duty spring. Existing .45 ACP magazines can be utilized with no modifications.

Handguns converted to .40 Super include the S&W 4506, Glock 21, Glock 30, SIG P220, FNH FNP-45, HK USP and the 1911 Government Model (and its variants). Handguns set up for the .45 Super cartridge only need a barrel swap. Handguns chambered for the .400 Cor-Bon can have their barrels rechambered to .40 Super at minimal cost.

Factory chambered handguns in the 1911 platform were introduced by STI. Barrel Reamers were produced by Clymer Mfg. Barrels and conversions were available from Bar-Sto Barrels, Jarvis, Inc., Storm Lake Machine, Cylinder & Slide, Al’s Custom, Inc., Morris Custom, LaRocca Gunworks, and EFK Fire Dragon. Reloading Dies are available from RCBS and Redding.



Current status
The .40 Super cartridge lost momentum when Triton Cartridge was sold and later closed. Double Tap Ammo and Underwood Ammo still offers loaded ammunition for the .40 Super. Today brass is still available from Starline Brass Company and DoubleTap, reloading dies are not available as of this year 2013 nor are 1911 conversion kits or barrels, the last known source was Bar-Sto Precision Machine. Lone Wolf Distributors and RockYourGlock still offer the conversion barrel for a Glock 21 and you must use a Glock 21 10rd singlestack magazine in order for the ammo to feed correctly, a doublestack 13rd magazine will not feed at all.

Related rounds

 * .45 Winchester Magnum
 * .45 ACP
 * .400 Corbon
 * .357 SIG
 * .38/.45 Clerke
 * .38 Casull