The bullets I used had a blue lube and the grooves were pretty thin.
I loaded with Trailboss too but for the BP loads, I put in a cookie under the bullet. Ended up using a .45ACP case for a dipper which iirc was right about 27gr of 3F. I didn't want anything too powerful since my 12y/o son was to be trying a bigger handgun for the first time. I thought it felt and shot just right and probably is close to the cowboy action loads.

Yes, my gun is manufactured as a cartridge gun and the 1872 was the first purpose built cartridge handgun which Colt made.
It falls between the Mason Richards cartridge conversions of Navy and Army cap and ball revolvers and the Single Action Army.