Strange marks on .357 cases :confused: (large pic)

40MM · October 21, 2006, 01:57 AM

Hi Guys, while de priming my .357 cases last night i noticed these strange marks on them. What could be causing this? The case on the right has not been de primed as yet. I am using a Lee Turret press with Lee dies. I notice a similar problem when loading my 9mm cases as well.

gary2905 · October 21, 2006, 03:57 AM

Try cleaning the dies.
Pull the decapping pin and clean the die like you would a gun barrel and see if the striation don't disappear.
If by strange marks you mean the line just above the rim, it is the limit of the sized region of the case, i.e., the lowermost travel of the case into the die.

40MM · October 21, 2006, 04:58 AM

Will try cleaning the dies like you say. By marks , i mean the long black lines on the two cases. Compare it to the case on the right.

cdoc42 · October 21, 2006, 08:37 AM

Probably powder fouling on the cylinder and case from firing, compressed onto the brass during resizing. Try a different powder that may be cleaner burning. What are you using now?

silicon wolverine · October 21, 2006, 02:11 PM

dirty dies. i have to clean mine about every 2500 rounds or the brass cojes out looking like that.

SW

40MM · October 21, 2006, 02:50 PM

the problem seemed to be dirty dies. cleaned it out and seems better. im using mp 200 powder.

JJB2 · October 21, 2006, 08:04 PM

also you might try a carbide sized die.... my lee dies have a carbide insert in the resizing sie and the brass comes out looking it has been cleaned again....

HSMITH · October 22, 2006, 06:46 AM

Crank your die down to hit the shell holder, then raise it one quarter turn. You aren't going low enough on the cases.

October 21, 2006, 01:57 AM	#1
40MM Member Join Date: April 15, 2006 Posts: 69	Strange marks on .357 cases :confused: (large pic) Hi Guys, while de priming my .357 cases last night i noticed these strange marks on them. What could be causing this? The case on the right has not been de primed as yet. I am using a Lee Turret press with Lee dies. I notice a similar problem when loading my 9mm cases as well.

October 21, 2006, 03:57 AM	#2
gary2905 Member Join Date: December 20, 2005 Location: Rural-not for long- Virginia Posts: 60	Try cleaning the dies. Pull the decapping pin and clean the die like you would a gun barrel and see if the striation don't disappear. If by strange marks you mean the line just above the rim, it is the limit of the sized region of the case, i.e., the lowermost travel of the case into the die.

October 21, 2006, 04:58 AM	#3
40MM Member Join Date: April 15, 2006 Posts: 69	Will try cleaning the dies like you say. By marks , i mean the long black lines on the two cases. Compare it to the case on the right.

October 21, 2006, 08:37 AM	#4
cdoc42 Senior Member Join Date: March 13, 2005 Location: Pennsylvania Posts: 1,687	Probably powder fouling on the cylinder and case from firing, compressed onto the brass during resizing. Try a different powder that may be cleaner burning. What are you using now?

October 21, 2006, 02:11 PM	#5
silicon wolverine Senior Member Join Date: April 28, 2006 Location: South dakota Posts: 674	dirty dies. i have to clean mine about every 2500 rounds or the brass cojes out looking like that. SW

October 21, 2006, 02:50 PM	#6
40MM Member Join Date: April 15, 2006 Posts: 69	the problem seemed to be dirty dies. cleaned it out and seems better. im using mp 200 powder.

October 21, 2006, 08:04 PM	#7
JJB2 Junior member Join Date: December 14, 2005 Posts: 558	also you might try a carbide sized die.... my lee dies have a carbide insert in the resizing sie and the brass comes out looking it has been cleaned again....

October 22, 2006, 06:46 AM	#8
HSMITH Senior Member Join Date: June 21, 2002 Posts: 2,019	Crank your die down to hit the shell holder, then raise it one quarter turn. You aren't going low enough on the cases.