I guess if you're using auto-rim cases you wouldn't have this problem, but I found myself avoiding Hercules powders like Unique, because I found them to be rather dirty, and if I wasn't careful on ejecting the cases and FM clip, I would get powder residue under the ejector that could keep me from being able to load a new FM clip and get the cylinder into battery.
I didn't have this problem using Olin 231 or Scot powders. Sorry, I don't remember the load, but I think that I did use the sort of bullets you mentioned. I didn't cast them myself, but IIRC, I used to get them from Bull-X. They were hard cast 255 gr truncated cone - flat nose - not really SWC, and they dropped into the cylinder beautifully, and they fed like a dream in my 1911s, and they'd take a bowling pin off a table like nobody's business!
Mark
I also use Alliant Red Dot in my 12ga. trap loads, and it's never let me down. The only other Alliant powder I use is 2400. I use it in .357, .45 Colt and .44 Magnum loads for both rifle (Winchesters) and pistol, and I also use it in cast bullet loads in 7x57, .303 Brit, 8x57, 7.62x54R, 30-30, .308 and .30-06 rifles. I love the stuff. Also, I'm old.
The only Alliant products I've never liked are Bullseye and Blue Dot. I've never been very successful with either.
You mentioned that you've got a 629. I load 8.5 gr. of Unique over an RCBS 44-250-K(ieth) which gives 1005 fps out of my flat-top and a friend took an elk (very quick and humanely) last season in Idaho with one of those loads in a Marlin lever gun.