Why do my reloads have black case necks?

I went up to Wilson Shoals today and shot for a few hours. I noticed that pretty much all of my 260 and 308Win case necks came out of the chamber black or darkened. According to my chrono, these loads are moving between 2650 and 2700 fps, so I don't think the loads are too mild to expand the case necks.

Any ideas?

Oh, BTW. Wilson Shoals is much nicer now to shoot at since they have a range master there. He may be a volunteer, but its nice to have someone controlling the range.

I would say it is the powder you are useing would be my first thought.

I reload some 308s with H4895 and they come out blackened but it don't seem to hurt the brass,, I clean them,,no problems.

I use Bullseye in 9MM and have the same problem. It cleans up however.

Are you wiping all the sizing lube off the necks as well as assuring that the chamber is dry and free from any oil / lube?

Sounds perhaps like the neck is expanding but not "gripping" against the chamber walls and gas is blowing by.

Dub said:

Are you wiping all the sizing lube off the necks ....

Click to expand...

Sounds like that to me..... keep the lube off the neck.

How many times have you reloaded the casings? Sounds like they are work hardened. Will only get worse as you reload them more. Been getting any split necks?

GAR

All of these cases have been thru the loading cycle a few times. No split case necks..yet. I do use Hornady's One Shot spray lube, so everything gets a little lubed, but I wipe off the necks with my fingers before sizing. I don't wipe down the rounds at completion.

I'll wipe the next batch down before I fire them to see if that solves it.

Work hardening was one of my thoughts too. I have never annealed case necks before, but I might give that a try. I do have reference materials on how to do so.

I hate to throw out good brass without a reason, but if I start getting split case necks, the whole batch is going into the trash.

Thanks guys.