Smokey Brass Help

[frankwright]

A friend gave me 500 Bayou 124 coated rn bullets. They would stick in his 9mm when trying to eject a live round.
I measured them at .357 so I decided to try them in my S&W 66.
I used Clean Shot powder, book lists 3.0-4.8 for a 125 lead RN Bullet so I loaded them at 4.4. I used a firm but taper crimp for the coated bullets as to not damage the coating.
I fired 50 at the range and they shot well and were accurate.
Yesterday I shot a pistol match and fired close to 200 rounds with no problem but noticed my cylinders were really dirty and the brass had some sooty streaks on it.
I am thinking this means unburned powder?
I have shot about 400 of almost the same bullet and powder in 9mm and found it to be clean.
Think my charge is just too low?

 

[transfixer]

only thing I can think of is the charge isn't enough to cause the brass to expand and seal the cylinder ?

 

[frankwright]

I will up it some and see if that helps.

 

[Gator89]

I ordered some .357 9mm bullets from Xtreme by accident. I use them to load my wife some light loads for her S&W 38 snubby.

 

[rosewood]

Is that powder a "copper fouling eraser" type powder? I have noticed a lot more soot when using CFEP. I think it is because the chemicals in the powder attaches itself to copper and brass (since it has copper in it) and I see a lot more soot on the brass when I use it than with other powders.

Or it could just be low pressure.

Rosewood