I've loaded up some .45 Colt in the following configuration for a buddy's new Uberti SAA clone. This load hit right where the sights were, and the recoil was pleasant, but on the other hand there was a strange issue where there was a great deal of partially burnt powder. I'd say about a total of 4-ish grains worth of partially burnt, yellowish powder was strewn across the table as I went through about 30 rounds or so of reloads.
*Powder: 7gn Win 231/HP-38
*Bullet: RCBS 200gn SWC .
(Designed for .45 ACP. Bullet sits about 0.21 inches deep in the case using a grease groove as a crimp groove)
*Large Pistol Primer
*Seated: 1.615 OAL
My guess is that Win 231 could be just too dense of a powder to use efficiently in .45 LC with that shallow of a projectile. What certainly does not help in the fact that the projectile is short and stubby in comparison to other more popular projectile types. I've got my eyes on a 255gn Flat nosed mold that keeps a good 2/3's of the projectile in the case. Could that improve the powder burn with a lower amount of air-space in the cartridge?
https://www.midwayusa.com/product/1010210353?pid=570018
Am I thinking in the right direction to potentially correct this issue?
All I've been able to grab in terms of powder is HP-38/Win 231. Would Accurate No5 be a potential candidate for a bulkier powder that may perform with a less unpleasant air-gap and more completely burn? I've heard the wonders of Unique but I've literally never seen it in stock when I've been looking for it.
Or, am I just barking up the wrong tree?