I have the same barrel, an octagon .45LC. The first thing I noticed was the greater recoil from the Contender - but it was not markedly faster than the same load fired in my revolver. That octagonal barrel has very thin walls, and weighs almost nothing. Attached to a frame with wood, the weight of the gun is about a pound lighter than my 10" bull .45LC with rubber.
Example, a 250 Hornady over 14.5 grains of Lil'Gun gave 995 fps in the 4 5/8" revolver, and 1100 fps in the Contender. But recoil was MUCH greater in the T/C. Due to the extremely thin barrel walls, I believe that using full powered loads recommended for the Contender is complete folly, risking a damaged barrel or worse. I use 250 SWC and 7.5 grains of WW231 in the octagonal barrel now - highly accurate with low recoil, and safe!