scorch marks on cases

Daryl licht

Long Range Savant
Full Member
Minuteman
Nov 22, 2012
107
4
Texas Hill Country
a friend has been churning out pistol ammo for us on his Dillon and it shoots amazingly. my question is though why are we getting what looks like a torch mark on one side of the empties. been happening with some 40's and a lot of the 9mm. hasn't been a problem reloading them but they almost look as if they've been annealed from the inside out and this is far below max on the powder charges. We have been using lead or plated lead bullets instead of jacketed if that makes a difference. never noticed it before on factory or military ammo.
 
Could be he has been using some powder a old guy gave him..I put up some pictures tomorrow thanks for your input. The cans he showed me looked like some my uncle was using in the late 60s. Damn I've been at this a long time.
 
a friend has been churning out pistol ammo for us on his Dillon and it shoots amazingly. my question is though why are we getting what looks like a torch mark on one side of the empties. been happening with some 40's and a lot of the 9mm. hasn't been a problem reloading them but they almost look as if they've been annealed from the inside out and this is far below max on the powder charges. We have been using lead or plated lead bullets instead of jacketed if that makes a difference. never noticed it before on factory or military ammo.

Low pressure isn't sealing the chamber and getting blow by.

Mr