I like RamShot Competition powder for 38 Short Colt and 38 Special . Measures good , fairly clean with no unburnt kernels to get under extractor and as accurate as anything else I've tried . I just cannot get Clay Dot , Clay's, American Select or e3 to measure accurately day in and day out from my 550. I've tried aquarium pumps small powder bar , polishing internals and just cannot get large flake powders to measure accurately . I might be too OCD( from my Benchrest shooting background) but 0.01 grs. or greater of variance are just not acceptable to me .