Dirty 9mm brass after firing

[Castinoff]

I know that brass doesn't have to shine to produce accurate ammo but I like it clean at least. In loading for my 9mm I've found a load of 2.6 - 2.8 gr. of Bullseye and a Lee 124 gr. TC boolit produce a pretty accurate round but the empty brass is filthy and tarnished with soot after firing. Is this normal? What can I do to reduce or eliminate this condition ?

[Crash_Corrigan]

What is the bore size of your shooting iron? I have a Browning Hi Power that when used with .356 or .357 cast boolits I got bad leading and lousey accuracy and a very dirt casing and gun. After abour 60 rounds or so the action was so gunked up that the gun would quit.

Sizing the boolits to .358 solved the problem. The other 9 MM, an EAA Witness will shoot the .356 just fine with good accuracy. Every gun is different.

[9.3X62AL]

Add-on to Crash's text.......your load is pretty soft, I suspect that the cases aren't expanding sufficiently to prevent propellant gases from leaking back onto the case sidewalls. Not a huge thing unless reliability is compromised, but I tumble my brass after every firing.

[HeavyMetal]

I'm surprised this load cycles the gun!

You need to bump up the powder charge a bit! Evey manual I have seems to start a 124 / 125 at around 3.9 grains of Bullseye to start! I agree with everyone else the load is to light to seal the case to the chamber walls!

By the way your brass will never come out of the gun as clean as it went in.