Opinion on black marks on 9mm cases

[Necro Monger]

Delete

 

[IM_Lugger]

whats the cause? As the case starts to move back/get ejected it gets licked by the burning powder gassed would be my bet. Very common.

 

[dusticles]

I was getting some marking like this in my Shadow with Blazer ammo but I had swapped out the recoil spring to work with my light hand loads. I assumed it was unlocking early with the faster ammo

Doesnt affect the brass any, it cleaned up in the tumbler. I would make sure to give the chamber a good cleaning every few hundred rounds though just in case the carbon is building up in there too.

 

[SLToronto]

My PPQ and SP-01 Shadow both do leave these marks, albeit a different length … CCI Brass 124gr being most commonly used ..
when ! started with PPQ, a guy at the range who was shooting PPQ for long, pointed to that "feature" ...

 

[Necro Monger]

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[Necro Monger]

delete

 

[Balance]

I get them with my glock 17, doesnt affect anything, ive loaded cases 10 times over and never cleaned them, still work perfectly!

 

[BCRider]

Try different ammo?

The soot is from the brass (or are you using aluminium cased ammo?) shrinking back down from a lowering of chamber pressure while there is still significant pressure in the barrel. So it leaks back between the casing and chamber walls. Different ammo with different burn rate powder might keep the pressure up for longer and that will keep the casing sealed against the chamber wall for longer until the bullet clears the barrel and the gases are directed more out to the front.

Or it may be that your Shadow has a slightly loose chamber size. That's not actually a bad thing. A slightly loose chamber won't be as inclined to bind up on a slightly bulged cartridge and fail to go into battery. Not a bad trait on a gun often used for competition.