get yourself one of those copper brillo dish scrubbing pads. cut a little square. wrap in around a brush on a rod. it will take all the lead out with little effort. then just oil and clean normally.
+1^^^^^
I've done this for decades, copper chore boy on a worn bore brush with a piece of clean rod. Chuck it up in a drill, takes less than a minute to clean all the cylinder holes. It's a mild form of barnishing.
Those rock hard bullets your using (24bhn) will leave carbon/lead rings in the cylinders every time with low pressure loads. I have no idea why oregon trail makes their bullets out of such a hard alloy. A 10bhn/11bhn bullet like the kind matt's bullets sells would be a better choice in lead bullets. Coated bullets would be another option.
A 200 round range session with coated bullets/38spl's in a 357.
No cleaning needed for another 600 or 700 rounds. 357's drop in the cylinders, no ring/build-up. But then again I'm using/shooting 9bhn coated bullets. Not 24bhn lead bullets.
Lyman uses an alloy called "lyman #2 alloy", it's 16bhn & is used for rifle bullets. A picture of 16bhn rifle bullets, one has been coated & the other was sized and traditionally lubed.
35,000+psi loads in a 308w with those 16bhn bullets pictured above.
borescope pictures of the 308w bbl
I couldn't even begin to count how many 44spl's I've shot in the 44mags. Same goes for 38spl's in the 357's. Always kept the alloy & lube soft. Some of my favorite 44spl plinking bullets.
The 220gr is a hbwc and the 175gr is a custom bullet that has different crimp/seating rings on both ends of the bullet. Seat that 175gr with the little end of the bullet sticking out in the 44mag cases & the big end sticking out in the 44spl cases. The end result is the same case volume/load/accuracy/oal with either case.
Anyway, use a softer bullet. You'll still get a ring built up in the cylinders. But it will take longer to form & yes you get the same ring built up with 44mag's or 357's for that matter. The ring is just further down in the cylinders/destroys accuracy. Nothing a bore brush with a piece of copper or bronze scrubbing pad wrapped around couldn't handle.