The .45 HP Load

by
posted on July 17, 2012
** When you buy products through the links on our site, we may earn a commission that supports NRA's mission to protect, preserve and defend the Second Amendment. **
wiley-clapp.jpg (3)

Many nations have enacted regulations that limit the possession of firearms and ammunition by their citizens—Thank God for the 2nd amendment. Some governments choose to prohibit just the possession of military caliber guns and ammo for civilian use. Regardless of intent or means of achieving same, this practice of no military guns in civilian hands sets clever minds a’working to evade the statute. American handgun aficionados are aware of the popularity of the 1911 pistol and .45 ACP cartridge in Central and South America, where it is often prohibited for civilians. In Mexico particularly, the answer is a 1911, but chambered in the .38 Super cartridge. An unknown, but significantly large portion of all Colt .38 Super pistol ended up south of the border and probably will continue to do so.

But the .38 Super is a long ways from the .45 ACP in the ballistic sense. When a similar situation arose in Europe in the early 1980s, clever minds devised a way to come up with a cartridge that would reproduce the exterior and terminal ballistics of the .45 ACP by developing a .45 round that would not fit into the chamber of a .45 ACP. Called the .45 HP, the round had a case almost identical to the.45 ACP, except in length. The round was shorter by about a millimeter and worked fine in a chamber cut deep enough to take it, but no deeper. If the chamber were deeper, a man could use .45 ACP ammo.

To deal with possible feeding issues, the .45 HP bullet was seated out of the case just a little in order to give the same overall cartridge length—1911 magazines worked fine. Pressures were slightly higher, which produced a little more velocity, around the 860 fps range. Also, the.45 HP was fitted with a small rifle primer. For a time, it looked like the round might do pretty well, with Geco, Fiocchi and Hirtenberger all making ammo with the 230-grain FMJ bullet. Colt may have made some retrofit .45 HP barrels, but I am unable to find any verifiable source that says they made complete guns.

It was a different thing at Smith & Wesson, which had just got into the big pistol business with the 645 and 4506. The Springfield, Massachusetts designers found that they could create a working .45 HP by installing a stock barrel, chambered for the HP cartridge. No other changes to breech face, extractor, etc. were necessary. An executive working at S&W at that time estimates that no more than a couple of hundred guns made for an Italian distributor in the late 1980s. It seems like a great deal of trouble just to get around government red tape.

Latest

Armasight Operator thermal riflescope
Armasight Operator thermal riflescope

New for 2026: Armasight Pro Series Thermal Platform

Armasight launches a professional-grade thermal-imaging platform designed to perform.

KelTec Launches KelTec Direct

KelTec begins its 35th anniversary celebration by launching KelTec Direct.

New for 2026: CVA Scout XP and XP-SB Rifles and XP Pistol

CVA expands its Scout line to include two single-shot rifles and a single-shot pistol.

Preview: Winchester After Hunt Dog Bed

Named after John Olin’s famed hunting dog, the King Buck product line exists within the larger Winchester Pet brand to showcase the company’s most deluxe offerings, and the After Hunt Dog Bed is a prime example of the line’s quality.

Review: CZ USA P10 Ported

CZ expanded its popular line of P10 handguns with a specially configured model that features integral barrel ports just behind the muzzle to aid in recoil management.

Keeping The Wilderness Quiet: Bergara's BTi30 Suppressor

Bergara joined the growing crowd of suppressor manufacturers in 2026 with its BTi30 design.

Interests



Get the best of American Rifleman delivered to your inbox.