about .460 rowland®

.460 Rowland® LLC is a Tulsa-based company and the proud purveyor of the only AUTHENTIC .460 Rowland® pistol Conversions.

We are the source if you are looking for True .44 Magnum Ballistics from your lightweight, easy-to-carry, high-capacity .45 caliber firearm.

about 460 rowland
460 rowland true 45 caliber round


Our history begins with our partner, Johnny Rowland, the man who conceived of and developed the round that bears his name. Working with a Government 5″ 1911 pistol, Johnny created the prototype .45 ACP Conversion that changed the pistol forever.

.460 Rowland® is what we do and all that we do.

We are based in Tulsa, OK where we take pride in giving every customer the personal attention they need and deserve. Sorry: No Robots and Phone Trees here….just a friendly team of people ready to help.

In addition to the signature 1911 5″ Gov’t Conversion for which we are famous, we also Convert 1911 Commanders and numerous other guns in both Compensated and Ported versions. Among them are the Glock 21, Glock 30, the Springfield Armory XD line and the Smith and Wesson M&P.

The .460 Rowland® is a true .45 caliber round, not actually a distinct caliber.

Only licensed and Authentic products may be marked or sold using our federally protected name and trademark … .460 Rowland®. Don’t be misled by pretenders in the marketplace. If you want to send a 185 gr bullet downrange at nearly 1600 fps with over 1000 pounds of energy, please: Call, Email or place an order Online and we will see that you can!


johnny rowland on motorcycle

“Years ago, when I first developed the .460 Rowland® cartridge, I was in Louisiana talking with a good friend of mine, an excellent gunsmith I had known and respected for many years.

He told me he had discovered that the .45 ACP would shoot just fine in my new .460 Rowland® barrel.

I have gone on to use this capability in actual practice and in my .460 Rowland® demonstrations ever since. I would think that after 16 or so years of experience in using the .45 ACP in my .460 Rowland® barrel and even mixing .45 ACP shells with my .460 Rowland® shells in the same magazine for practical and demo purposes, I should know by now whether or not it would be functional or rational to do so.

It is. And this is certainly a useful feature of the .460 Rowland® barrel-shell-gun concept: for Converted guns to also be able to shoot the common .45 ACP ammo in addition to our Magnum power .460 Rowland® ammunition.” Your Friend Johnny Rowland


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.

This is similar to the relationship between the .357 Magnum and the .38 Special. 
There are two key elements to the .460 Rowland® concept.

The first is a sharp increase in cartridge maximum pressure over the .45 ACP and .45 Super. Maximum Average Pressure is: 45 ACP (21,000 PSI), .45 ACP +P (23,000 PSI), .45 Super (28,000 PSI), .460 Rowland® (40,000 PSI). The second is to damp or reduce the velocity of the slide in converted autoloading pistols to manageable levels.

The first delivers magnum level performance and the second allows the cartridge to be easily and reliably fired from compact, light weight, high capacity, autoloading pistols.


The increase in slide velocity over a standard .45 ACP, or even a .45 Super round, cannot be properly controlled with an increase in recoil spring rate alone.

Autoloaders properly converted to fire the .460 Rowland® Cartridge require a compensator or a ported barrel to ensure reliable, long lasting, operation.

This fact not withstanding, there continues to be customer demand for a “stock-looking” .460 Rowland® conversion; however, any effort to answer this demand is thus-far not supported by the Inventor.

Rowland still maintains that a properly designed .460 Rowland® Conversion requires an effective compensator to momentarily delay slide action until the very high pressures developed by his cartridge dissipate to more manageable levels.

Without this compensation, slide or frame failure will result over time and reliability will suffer in the short term. 

High quality 1911 auto-loading pistols are manufactured by many different companies and tolerances vary with each manufacturer.

As a result, adjusting recoil spring tensions and identifying specific magazines that works best in each individual gun have always been necessary to insure optimum performance from this 112 year old design.

These same considerations are no less important when converting these guns to fire .460 Rowland® cartridges. Once installed, tested and adjusted in this manner, a 1911 / .460 Rowland® Conversion will shoot .45 ACP, +P, Super and .460 Rowland® cartridges accurately and reliably without ever having to revert to the factory barrel.

Springfield XD / XDm, Glock 21 and Glock 30 auto-loaders and the SIG Sauer P220 are all made by a single manufacturer so similar adjustments are not often needed when these guns are converted to fire the .460 Rowland®. 

The Ruger Blackhawk and Smith & Wesson Model 25/625 can also be chambered to fire the .460 Rowland®. These conversions require 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 made 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 and are very accurate fire arms. 

Works With: 1911 Models, Glock 19, Glock 21, Glock 30, Springfield XD, Springfield XDm.


.460 Rowland® CONVERSIONs



.960 Rowland®




14 + 11 =


420 S. Main Street, Suite 204 Tulsa, Oklahoma 74103

(918) 928-7460

Due to heavy call volume, an email may get you faster service for questions.

If you wish to place an order over the phone, we will do our very best to assist you



We cannot be responsible for failures to cycle or for gun damage resulting from hand loaded ammunition; nor from the failure to install our products according to our guidelines and using all specifically recommended parts and accessories.