My Early 15-2 Dan Wesson (357), was Never too great with my cast boolits.. I finally discovered (lazy) that the cylinder throats were Waaayyy small for the Barrel Slug. I checked more carefully due to obtaining a 2-1/2 inch Barrel and Shroud, along with some other "stuff" among which was a Cylinder on crane. I slugged the little barrel, (easy to do with just barrel on bench), and found that the Slug Fell thru the Cylinder!!! Welp, of course this prompted me to try the Slug in the Currrent 6" barrel and Cylinder...
Wonder of wonders...sorry Doug., may Not need you on this one. Fits Good. My current 6" barrel is currently paired with the "spare" cylinder (yes cylinder only, using old extractor and "star") now have larger Cylinder with Larger Barrel, and it shoots even better than it ever has with Cast!!! I'm elated...Next to pair the tight Barrel and Cylinder...another Day. I'm mowing lawn today...whats left of today.
Yes, I may need to resize for smaller throats and bore...Maybe...as said, another day!