Walks - thanks or that explanation. I just bought some loaded cartridges in 45 Colt from a member on here - not knowing the loads, I pulled the 255 gr RNFP and dumped the powder. It was mixed head stamp brass and I noticed about three or four with the channeler on the brass as you describe - don't recall the head stamp.
I bought some commercial wadcutter cast boolits a while back for the 45 Colt to try out - I haven't gotten around to loading anything but a couple of dummy rounds in Starline brass. Seemed to seat just fine and I just roll crimped in to the top ring.