.460 Rowland

From Wikipedia, the free encyclopedia
Jump to navigation Jump to search
.460 Rowland
Type Pistol
Place of origin United States of America
Production history
Designer Johnny Ray Rowland
Designed 1998
Case type Rimless, straight
Bullet diameter .451 in (11.5 mm)
Neck diameter .473 in (12.0 mm)
Base diameter .467 in (11.9 mm)
Rim diameter .480 in (12.2 mm)
Rim thickness .049 in (1.2 mm)
Case length .960 in (24.4 mm)
Overall length 1.275 in (32.4 mm)
Case capacity 25 gr H2O (1.6 cm3)
Rifling twist 1 in 16 in (406 mm)
Primer type Large pistol
Maximum pressure (C.I.P.) 38,000
Maximum pressure (SAAMI) 40,000 psi
Ballistic performance
Bullet mass/type Velocity Energy
185 gr JHP[1] 1,500 ft/s (457 m/s) 924 ft·lbf (1252 J)
230 gr JHP 1,300 ft/s (396 m/s) 863 ft·lbf (1170 J)
Test barrel length: 5"

The .460 Rowland cartridge was designed and trademarked by Johnny Ray Rowland, host of The Shooting Show. The development of the 460 Rowland cartridge is attributed to his friend Jim Clark of Clark Custom Guns, the purpose of the cartridge is to enable .44 Magnum power and performance in lightweight, high-capacity, semi-automatic handguns.[2]


Rowland brought the idea for the cartridge to his friend and noted pistol-smith Jim Clark to develop the conversion. Rowland then collaborated with Starline Brass to finalize commercial production of the casings, he first commercially distributed ammunition and conversions for the 1911 semi-automatic handgun in 1998 and became a partner in .460 Rowland LLC.


The .460 Rowland case is approximately 1/16" longer than a conventional .45 ACP case, but the overall cartridge length is the same; the bullet is simply seated more deeply. The purpose of the extended case length is to prevent the high pressure .460 Rowland from being chambered in a standard firearm chambered for the low pressure .45 ACP.

The .460 Rowland cartridge sharply increases chamber pressure and gas volume when compared to .45 ACP cartridges, which drives projectiles to much higher velocities than a .45 ACP. A compensator on the muzzle-end is required to momentarily lock slide action in order to vent gas pressure, allowing the slide to operate under near normal pressures. Higher chamber pressures deliver magnum level performance while the imperceptible delay in slide action allows the cartridge to be fired from many compact, lightweight, high capacity, autoloading pistols.


Model 1911 pistol with .460 Rowland conversion. The 1.5" compensator works in conjunction with a 22 to 24 pound recoil spring to control slide velocity and recoil.

The company offers ammunition and conversions for various .45 ACP firearms. Among them are: 1911 5" Gov’t Model and 4.25" 1911 Commander, both made by numerous manufacturers; Glock-21 and Glock-30; Springfield Armory XD/XDm line, including 3.8" Compact, 4" Service Model, 4.5" Full Size, 5" Tactical, and 5.25" Target Model. The slim-lined Smith and Wesson M&P, both full size and compact, can also be converted.[3]

Companies authorized or licensed to offer 460 Rowland products are .460 Rowland LLC (Tulsa, Oklahoma), Starline Brass (Sedalia, MO), Underwood Ammunition (Sparta, IL), Tombstone Armory LTD, (Tombstone, AZ), and Clark Custom Guns. Others are in evident violation of federal patent and trademark law.[3]

Autoloaders converted to fire the .460 Rowland Cartridge require a properly designed compensator or ported barrel. Ported barrels have proven viable in managing the power of the cartridge, but result in somewhat more muzzle flip and felt recoil.[3] Ported barrels can be more readily installed or removed from the slide (moot in a 1911 due to its design)—legal in restrictive states like California—without needing to permanently secure the compensator to the barrel.[3][4]

High quality 1911s are manufactured by many different companies and tolerances vary with each manufacturer, it is necessary to adjust recoil spring tensions and to identify specific magazines that work best in each gun. This must be done when converting a 1911 to fire the .460 Rowland cartridge. The company says a properly designed conversion requires an effective compensator to momentarily delay slide action and allow very high pressures and volumes of gas to dissipate to manageable levels before slide action may begin. Without this compensation, slide or frame failure will likely result over time and reliability will suffer in the short term.[3]

The Ruger Blackhawk and Smith & Wesson Model 25/625 can also be chambered to fire the .460 Rowland. Converting these revolvers requires deepening the chambers and is effectively permanent, unless the owner has a replacement cylinder fitted, for several years Dan Wesson also made a revolver specifically for the .460 Rowland, which would also chamber .45 ACP, .45 Super and .45 Winchester Magnum, as does the Smith & Wesson Model 25/625. Both guns use moon clips. Rowland does not support customer demand for "stock-looking" .460 Rowland conversions.[3]

See also[edit]


  1. ^ .460 Rowland LLC
  2. ^ MGImilitary (2009-01-07), Johnny with MGI, retrieved 2016-12-20 
  3. ^ a b c d e f Thomas Scriminger, President, 460 Rowland® LLC, holder of the federal trademark
  4. ^ http://www.460rowland.com/product/ported-xdm-4-5/

External links[edit]