Got Black

[bornintheeu]

After shooting I’ve got black soot on my 9mm cases, reloaded with 4gr of N320.

Could it be due to a light crimp? Low pressure? Or to the gun, a CZ75 SP01 Shadow?

 

[Havok7416]

Your cases are not sealing which is a direct result of the pressure being too low to allow the case to fully expand. It's not a problem per as, but if you are having any accuracy or cycling issues it may be something to address.

 

[Rule3]

I would help to know the type and WEIGHT of the bullet?

 

[bornintheeu]

LOS RN 124 gr

 

[Rule3]

I would help to know the type and WEIGHT of the bullet?

I do not know what LOS is?

Lead or jacketed?? Regardless as others posted it "appears" your load is to low (maybe even below the start load.)??

If so, it is incomplete combustion and not enough to seal the brass in the chamber.

What data are you using?

Here is VV data:

http://www.vihtavuori.com/en/reloading-data/handgun-reloading/9-mm-luger.html

 

[higgite]

LOS is a copper plated bullet, similar type as the Ranier bullets in the VV tables. Another unknown to us is the COL of the sooty rounds. Which may not do us any good to know anyway unless we know how the bullet length/seating depth compares to a Ranier in the VV tables.

 

[Walkalong]

I use 3.9 to 4.0 Grs N320 with a 124 gr plated bullet and the cases are very clean, except in the blowback action AR.

I would make sure I had good neck tension, the OAL wasn't too long, maybe a primer change........check the scale.....