Why is my brass dirty?

[smith629]

I shot some 38spl reloads out of my Henry big boy rifle (125gr hornady xtp with 5.5gr unique, cci #500) but noticed the brass was very dirty. It has carbon about half way down the body starting at the neck. However, the same reloads are clean out of my 2" revolver.

Any idea why that would happen? Perhaps the unburned powder is trapped in the barrel instead of immediately existing the revolver? Sorry if this is a dumb question but I'm a bit new to reloading for pistols.

[Bainter1212]

Your lever gun probably has a slightly roomier chamber allowing some gas to creep around the cartridge. Nothing to worry about.

[fguffey]

When I fire a round I want tthe case to expand and seal the chamber. When the case does not expand and seal the chamber I suspect low pressure. The problem can be caused by slow burning powder.

It is possible for the gas that is trapped between the case and chamber to crush the case.

F. Guffey

['ol shooter]

Big chamber, low power load, or both. I load my stuff middle of the chart for handgun, and they all show a little exterior marking like yours.

[wbunning]

Burns/powder stains will occur on the case when it fails to quickly expand, or obturate, to completely close off the chamber before the powder is combusted. Conditions that cause that are most commonly related to low pressure as mentioned above , which can be caused by light charge, slow powder, ill-fitting bullets, etc.

[smith629]

Great thanks for the advice everyone. I will try adding some extra powder to the charge weight and see if that fixes it.

[ar15barrels]

I shot some 38spl reloads out of my Henry big boy rifle (125gr hornady xtp with 5.5gr unique, cci #500) but noticed the brass was very dirty. It has carbon about half way down the body starting at the neck. However, the same reloads are clean out of my 2" revolver.

Any idea why that would happen? Perhaps the unburned powder is trapped in the barrel instead of immediately existing the revolver? Sorry if this is a dumb question but I'm a bit new to reloading for pistols.

The pressure is too low to properly expand the case and seal the chamber.
Since the case was not expanded, the gas/burning powder gets on the outside of the case in the chamber and leaves the black staining.
Increase your load until the cases come out cleaner.

Cartridge          : .38 Special (CIP)
Bullet             : .355, 124, Hornady HP/XTP 35571
Useable Case Capaci: 18.772 grain H2O = 1.219 cm³
Cartridge O.A.L. L6: 1.550 inch = 39.37 mm
Barrel Length      : 16.0 inch = 406.4 mm
Powder             : Alliant UNIQUE

Predicted data by increasing and decreasing the given charge,
incremented in steps of 3.333% of nominal charge.
CAUTION: Figures exceed maximum and minimum recommended loads !

Step    Fill. Charge   Vel.  Energy   Pmax   Pmuz  Prop.Burnt B_Time
 %       %    Grains   fps   ft.lbs    psi    psi      %        ms

-33.3   36     4.00   1038     297    7925    922     96.9    1.908
-30.0   38     4.20   1078     320    8599    967     97.9    1.834
-26.7   39     4.40   1117     343    9305   1009     98.6    1.766
-23.3   41     4.60   1154     367   10044   1050     99.2    1.705
-20.0   43     4.80   1191     390   10815   1088     99.6    1.649
-16.7   45     5.00   1226     414   11618   1123     99.9    1.597
-13.3   47     5.20   1260     437   12455   1156    100.0    1.549
-10.0   48     5.40   1294     461   13326   1187    100.0    1.504
-06.7   50     5.60   1326     484   14231   1218    100.0    1.489
-03.3   52     5.80   1357     507   15171   1249    100.0    1.446
+00.0   54     6.00   1388     530   16145   1280    100.0    1.406
+03.3   56     6.20   1418     553   17155   1311    100.0    1.369
+06.7   57     6.40   1447     576   18201   1342    100.0    1.333
+10.0   59     6.60   1475     599   19284   1373    100.0    1.300  ! Near Maximum !
+13.3   61     6.80   1503     622   20403   1404    100.0    1.268  ! Near Maximum !
+16.7   63     7.00   1531     645   21560   1434    100.0    1.238  !DANGEROUS LOAD-DO NOT USE!

Results caused by ± 10% powder lot-to-lot burning rate variation using nominal charge
Data for burning rate increased by 10% relative to nominal value:
+Ba     54     6.00   1419     554   18407   1238    100.0    1.331
Data for burning rate decreased by 10% relative to nominal value:
-Ba     54     6.00   1341     495   13884   1337     99.7    1.485

[stilly]

Your lever gun probably has a slightly roomier chamber allowing some gas to creep around the cartridge. Nothing to worry about.

By jobe i think this might be in line with the answer...

[tonyjr]

If I don't crimp right [ to light on 44mag and to heavy on 50 AE ]
I get the smoke on cases .
On the 357 , I have not figured out why on both the desert eagle and the revolver with the nickel cases .