The word “magnum” started off as a Latin word meaning “large, great, or important.” In the modern-day ballistics context, Merriam-Webster defines “magnum” as “a cartridge equipped with a larger charge than other cartridges of the same size.”
This primarily has been the provenance of revolver cartridges, from the original .357 Smith & Wesson Magnum in 1935 to the .44 Remington Magnum in 1955, the .41 Remington Magnum in 1964, running all the way up to the behemoth .500 S&W Magnum in 2003. A good number of Magnum caliber autopistols, like the first three Desert Eagles as well as the 1911-style Coonan Arms, have been chambered in these calibers.
That said, a fair share of Magnum-powered cartridges have been dedicated semiautomatic pistol cartridges from their inception. Let’s take a look at the five most powerful of the bunch.
.50 AE (Action Express)
Might as well start with the biggest and baddest boy on the block. After releasing the .357 Magnum Desert Eagle in 1983 and the .44 Mag chambering in 1986, Magnum Research of Fridley, Minnesota decided in 1991 to go a different and bigger route with a newer, autopistol-specific cartridge.
Enter the .50 AE, invented in 1988 by Evan Whildin of Action Arms. Using a 325-grain jacketed hollowpoint round at a muzzle velocity of 1400 feet per second (fps) from a 6-inch barrel, it generates muzzle energy is 1414 foot-pounds.Even at 100 yards the figures are a still-impressive 1138 fps and 930 ft. lbs.
I myself fired a .50 AE Desert Eagle on my 18th birthday back in 1993, and it was pretty goshdarn unforgettable.
.44 AMP (AutoMag Pistol)
The original semiauto Magnum cartridge and handgun was first made famous by bestselling author Don Pendleton and his character Mack Bolan in The Executioner series of action-adventure novels in the 1970s. It received a further boost from Clint Eastwood as Dirty Harry Callahan.
Gun and cartridge alike were invented by Harry Sanford in 1970. In the process of invention, Harry took empty .308 Winchester or 30-06 Springfield brass cases, cut them to length, and loaded a .429-inch diameter bullet into the case mouth. The resultant muzzle velocity and energy are reportedly 1,600-1,800 fps and 1,500 ft. lbs. respectively.
Unfortunately, due to logistical mismanagement and poor marketing strategy, the AutoMag was a financial failure. Thankfully, in 2015, along came Auto Mag Ltd., Co., which is not only reviving the pistol but also promising a smarter marketing strategy to keep the product financially viable this time.
.45 WinMag (Winchester Magnum)
First, take your standard tried-and-true .45 ACP 230-grain full metal jacket “hardball” cartridge. Then marry it with a .45 ACP cartridge case that’s been lengthened from 0.898 inches to 1.198 inches to accommodate a significantly greater power charge. Next, double down on the muzzle velocity, kicking it up to 1,600 fps, accompanied by a muzzle energy of 1,200 ft. lbs. Your end result is the .45 Win Mag, developed by Winchester in 1977.
For a gun to serve as the cartridge’s launching platform, fast-forward to 1983, when L.A.R. Mfg. Inc. designed the Grizzly pistol, which is basically an M1911 on steroids, HGH, and creatine mixed into a cocktail. I fired one back in December 1990 at the age of 15, and I daresay it was an even more memorable shooting experience than the .50 AE. In a hilarious case of life imitating art, suffice to say for now it evoked the range scene from the original RoboCop movie.
Sadly the Grizzly was discontinued in 1999, but ammo in the caliber is still available online.
.475 Wildey Magnum
This is yet another Magnum auto that gained fame from a movie — this time Charles Bronson’s Paul Kersey in Death Wish 3. Named for inventor Wildey J. Moore, the cartridge was designed in 1977, but the pistol didn’t actually debut until 1984.
The two configuration options for the caliber were: a 250-grain bullet with a muzzle velocity of 1,850 fps and 1,900 foot-pounds of muzzle energy, and a 300-grain bullet at 1,610 fps and 1,727 ft-lbs. These rounds wield more ballistic energy at 100 yards than the .44 does at the muzzle!
As with the .44 AutoMag, the Wildey had been discontinued, but is now making a comeback, in this case thanks to USA Firearms Corp., who has symbolically renamed the gun “the Survivor.” (They’re also making it available in .45 Win Mag.)
.429 DE (Desert Eagle)
Not content to produce its Desert Eagle pistols in calibers invented by other companies, Magnum Research decided to conjure up its own original cartridge in 2018. As per Magnum Research spokesperson Monica Arnold back in October of that year:
“Magnum Research has developed a new, fast, powerful .44 caliber pistol cartridge. The 429 DE (Desert Eagle) was designed to enhance the famous and powerful Desert Eagle platform. This cartridge has a 25% velocity increase and 45% energy increase over a 44 Mag (240 — 6″ barrel). It has a velocity of 1600 FPS with 240 grain bullets and 1750 FPS with 210 grain bullets…’This new cartridge was engineered and designed specifically for the Desert Eagle Pistol, keeping in mind that the DEP is known world wide for its awesome firepower and performance. The 429 DE propels that history into the future,’ says Jim Tertin, Design and R&D for Magnum Research.”
Christian D. Orr is a Senior Defense Editor for 19FortyFive. He has 34 years of shooting experience, starting at the tender age of 14. His marksmanship accomplishments include: the Air Force Small Arms Ribbon w/one device (for M16A2 rifle and M9 pistol); Pistol Expert Ratings from U.S. Customs & Border Protection (CBP), Immigration & Customs Enforcement (ICE), and the Federal Law Enforcement Training Center (FLETC) Criminal Investigator Training Program (CITP); multiple medals and trophies via the Glock Sport Shooting Foundation (GSSF) and the Nevada Police & Fires Games (NPAF). Chris has been an NRA Certified Basic Pistol Instructor since 2011.