Owner of Buffalo Bore Tim Sundles on 460 Rowland Ammunition:
The 460 Rowland, as we load it, is squarely at mid-44 magnum power levels. This means that a person can now carry a 1911 style combat pistol that has the power of a 44 mag. revolver, but is slimmer, faster to reload, faster to shoot and holds nine rounds instead of a revolver's six. The 460 Rowland casing is simply a 45 ACP case that has been slightly lengthened so it won't chamber in a 45 ACP chamber. It also has a stronger web area in the casing, so as to avoid "blow outs".
To acquire 460 Rowland test guns, I sent two of my 1911 45 acp pistols to Clark Custom Guns and had them install their 460 Rowland conversion kits. To date the converted 1911's work great. I can fire a 255gr. hard cast bullet @ 1300 fps or a 230gr. FMJ-FN bullet @ 1350 fps. What a great "woods" pistol that still maintains combat pistol qualities.
We are using flash suppressed powders in each 460 Rowland load, so that if you have to shoot in the dark, the muzzle flash will not blind the shooter and we feel this feature is a big tactical advantage.
Note my real world velocities (below) from real world pistols, not laboratory test barrels.
Colt series 70 govt. mod. 5 inch with Clark 460 conversion
Colt 2009 circa Gold Cup govt. Mod. 5 inch with Clark 460 conversion
It should be noted that my 460 Rowland conversions are Clark Custom conversions. I did not try this ammunition in conversions manufactured by anyone other than Clark. This ammunition was reliable and safe in my test conversions, but I cannot verify the reliability or safety of this ammunition in conversions done by anyone other than Clark Custom.