I posted some 10mm data a few days ago, and figured Ill post the 460 Rowland data. The ammo was loaded in about 3 different lots, I cannot differentiate from them, but I do know they all had 12.3 grains of Power Pistol in them (max 12.5 per 460rowland.com). On a side note, I was having feeding problems so I ended up putting a crimp on the ammo, and polished the feed ramp. Also you gotta give the gun a firm grip to make the gun feed reliably. Its a Glock 21 3rd gen that I converted.
230 gr Hornady xtp
1289
1306
1310
avg 1301 energy 865
230 gr Hornady RN
1310
1259
1297
avg 1288 energy 1847
I have choreographed some ammo that was loaded to the max. I never wrote down the numbers but they were getting between 1330-1350 fps. Either way the gun is surprisingly accurate considering what you are shooting out of a semi auto polymer frame.