Hey folks, this is really not a reloading topic but I'm posting here since it involves fired cartridge/black soothe on the brass.
Below pic has 2 spent 9mm 115gr fmj brass. They were fired out of my brand new Gen4 G34. The one on the right is the first shot I ever took with the pistol (I keep the first brass for all my guns for sentimental reasons).
As you see there is blackness towards the top of the case but it's only for 1/4 to 1/3 of the way around and only towards the top of the case. Now take a look at the one on the left. That one was probably between shot number 20 to 60. and the blackness is same width but almost the entire length of the brass, and much darker/intense.
These are not reloads but brand new ammunition in the box. The one on the right was CCI Blazer and the the left was Federal. I've shot also Remington, PMC & Winchester on the first day and almost all brass was like this.
Now I know that when the charge in the ammunition is low, the case doesn't get pressurized/expanded enough and doesn't expand to the entire width of the barrel, hence there is a small air pocket between the case & the barrel, and the hot gasses scorch that area, causing such blackness/soothe. But I doubt that'd be the case for 100 rounds from 5 different manufacturers...
Also what I noticed is that the soothe won't come off with finger/spit rub, meaning it's really there - it's not just a small layer of dust. I don't tumble/reload so I don't care much about the brass, but am wondering if this is normal or an area of concern...
Cheers
Below pic has 2 spent 9mm 115gr fmj brass. They were fired out of my brand new Gen4 G34. The one on the right is the first shot I ever took with the pistol (I keep the first brass for all my guns for sentimental reasons).
As you see there is blackness towards the top of the case but it's only for 1/4 to 1/3 of the way around and only towards the top of the case. Now take a look at the one on the left. That one was probably between shot number 20 to 60. and the blackness is same width but almost the entire length of the brass, and much darker/intense.
These are not reloads but brand new ammunition in the box. The one on the right was CCI Blazer and the the left was Federal. I've shot also Remington, PMC & Winchester on the first day and almost all brass was like this.
Now I know that when the charge in the ammunition is low, the case doesn't get pressurized/expanded enough and doesn't expand to the entire width of the barrel, hence there is a small air pocket between the case & the barrel, and the hot gasses scorch that area, causing such blackness/soothe. But I doubt that'd be the case for 100 rounds from 5 different manufacturers...
Also what I noticed is that the soothe won't come off with finger/spit rub, meaning it's really there - it's not just a small layer of dust. I don't tumble/reload so I don't care much about the brass, but am wondering if this is normal or an area of concern...
Cheers
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