9mm Luger

[otter25]

Some,not all of my reloaded and fired cases are black along one side of the fired case. What causes this, possibly crimp related? All my loads function flawless.

 

[FOTIS]

Unburnt power. What is your load?

 

[otter25]

5.5gr Win Autocomp, 115gr Rainier HP and Win primers.

 

[FOTIS]

Well that is a hot load so I do not think it is a light load.

 

[otter25]

I have Hornady Custom taper crimp dies and am going to set the crimp just a bit more.

 

[otter25]

I have set my crimp at .3755, tried dropping my charge of Autocomp from 5.5 to 5.3 and cases are still black along one side. Factory loads do not do this. Ideas would be appreciated.

 

[Wyo7200]

My 9mm does it too, if it's on the outside of the case. It's powder burning the next round as the case is ejected. My g9 carbine soots them up pretty black. It tumbles off and the brass is ok.