lead deposits on fired cases?

[smlekid]

I hope this is in the right forum I have just started loading for my 9mm it is a Norinco M213 the bore slugs at .357" and I am loading the Lee 124gr TLTC Boolit with 4gr of Hodsgons Universal accuracy seemed ok but on loading the fired cases discovered a deposit that is best desrcibes as melted lead on the case mouth?
I haven't struck this before the loads are on the hotter side so I have reduced it to 3.5gr the bullet alloy is a bit of an unkown they were store purchased 44/40 hardcast and seem fairly hard to mark with my finger nail they drop at .357" and weigh 122gr anyone shed some light on this?
I have loaded many rounds for Rifle Shotgun and pistol but this is my first go at 9mm and also the first time I have seem the lead on case mouth it has me a little bewildered???

[SciFiJim]

Did you also have leading in the barrel? I would think that if you had melted lead in the case it would also carry into the barrel. From what I understand, there is not enough time to melt lead, even at the high pressures generated when firing. Could it have been shaved off by a small burr or deformity in the case mouth?

[MtGun44]

Deposits in the cases shouldn't be an major issue. Tumble the brass and see
if there is a permanent build up that might be of some slight concern.

Are you getting any leading in the bore? If not, shouldn't be a problem.
.357 boolits in a .357 bbl is just on the bottom edge of a good fit. You will
usually get best accy and least leading from .001" to .002" larger than
groove diam. With a soft enough boolit, you can get undersized boolits
to work well since they can bump up to fit as the pressure comes up.
This is why undersize and hard is the worst combo - unfortunately pretty
common with commercial cast boolits.

Ultimately, if you have good accy, no leading and the only issue is a bit
of deposit in the cases, you are doing well.

Bill

[runfiverun]

most commercial is 2% tin and 6% antimony.
a real good candidate for cuttting with pure or ww's.
when they were cheap i would buy commercial cast and re-melt to make varmint boolits for my rifles.
you might want to check that you aren't creating the lead deposits when seating your boolits you might just be ironing the lead to the case mouth upon firing.

[looseprojectile]

I just had the same thing happen on some .375 H&H magnum brass. Lead plated on the outside of case mouth, up to about an eighth of an inch back.
I attribute this to the boolit being too soft and way too much and too fast powder.
I was using Unique though the effect would be the same.
Over the years I have seen the same thing in revolvers where the front of a cylinder would become solidly plated with lead when the load was too hot or the alloy was soft. At the same time time the face of the cylinder was leaded the cases had some lead on the outside of the case mouths.I don't think the lead melts. I think this is caused by too much pressure for the soft alloy. I am going to go to harder boolits or slower powder, or both to solve my issue.

Life is good