Interesting find

[adam_mac84]

Having successfully developed loads for a couple of previous glocks, and a compact S&W, when I got my 5" SW I figured... no problem.

Well, multiple alloys, sizes, oal, crimps (no crimp, fcd etc) and powders later, I was still getting leading (about 1/3 barrel).
(for info sake. Size is always after PC)

I am not sure why, or for what reason, I double coated a batch of COWW.

Shot them. 99% of leading was gone

Tried same with range scrap.

Very little leading again. Came out with cleaning brush.

I guess I am not going to screw with success. I may try ESPC, as maybe this exposed problems with my dry tumble method... But an interesting find none the less. Can't say why, but it seems to help. Just takes an extra few minutes at the toaster oven on a casting day

[Grmps]

I assume the PC passed the smash test and I also assume you slugged / pound casted the barrel and are sizing at least 1 thou over the size (somtimes you need to go 3 thou over depending on alloy and how hard your pushing it..
What caliber is the S&W?

[adam_mac84]

It's been a difficult M&P 9mm. yes, slug and smash test and whatnot (.3555, sizing .357 and .358 through testing). All the steps I have taken for previous 9mm and other M&Ps. The .358 double coated shot like butter (for me). scored 100 at 15y on B8 which is a pretty good load/shoot for my hands.

I think I was just doing a crappy job with Smoke's powder... am happy it is working finally! 3 gun this weekend