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
Good question you have there, Bocadan. For what it's worth, let me share my thoughts on this: 1. The first rounds you fire will have the cleanest cases, because the chamber itself has not been contaminated with residues. 2. These residues can include vaporized contaminants from gunpowder, the primer, and the jacketting of the bullet. 3. The residue, and smoke, and carbon, escape into the action when the case is extracted from the chamber. 4. These residues then cling to the next rounds chambered. 5. Some ammo manufacturers, you will find, use gunpowder that burns dirtier than others, Remington UMC comes to mind at the top of the list of dirty ammo, with Fiocchi (at least in 9mm) as one of the cleanest in my experience. That info may be out of date, since I reload and have not fired factory ammo in years. To find out which is the "dirtiest" ammo, look inside the case after firing, not outside. Hope that helps. Cheers!
Oh, and dirty ammo will not adversely affect your Glock, it just means you need to clean it after every range session, which is a good rule to follow in any case.
Thank you Happy Sniper. I always see you provide valuable assistance to all the members here at the forum. So just one quarter of the surface of the brass being extra black and the the rest 3/4 being sparkly clean is normal and no area of concern? With my noviceness I was under the assumption that the soothe should have been more equally distributed... I've rented different 9MMs at the range many of times and fired thousdands of rounds but never paid much attention to the brass there. But this being my first Glock & first 9MM, I was just curious...
I've seen 9mm brass (UMC) with soot and scorching down to nearly 3/4 the length of the case but on one side only, and it's still good. It does not get hot enough long enough to affect the metallurgy of the brass, it just gets the insides of the pistol real dirty. Oh, try this, too: shoot ONE round thru a newly cleaned gun, then disassemble and inspect the bore. You will find visible particles clinging to the insides of the bore....primer and gunpowder residue adhering to vaporized lubricant residues in the barrel. It's normal. By the way, let me say that an overabundance of caution is a very good thing to have, especially with a firearm. Good job noticing and wondering about the brass filth. Cheers!
