Casing issue at primer

Sgt Pepper · January 21, 2013, 07:50 PM

What issue is indicated by the condition of the primer area of these casings? Thanks.

wncchester · January 21, 2013, 08:00 PM

Nothing. Your firing pin hits are a bit erratic in depth and that suggests some of your cases may be a bit short but if they fire they're fine. ??

243winxb · January 21, 2013, 08:03 PM

"Primer wipe" is a teardrop-shaped firing pin impression, accompanied by a drag mark (scratch or gouge) following the "point" of the teardrop and leading away from the primer, sometimes into the brass. This is because the firing pin does not fully retract after the round has fired and the slide is traveling back during ejection, causing the case to drag across the firing pin as it is thrown clear. It is not in any way harmful, except sometimes to the case if the primer pocket edge is gouged. Kahr will tell you it is a normal condition for their pistols, even saying so in the owner's manual. [IMG]

[/IMG] click for larger photo.

243winxb · January 21, 2013, 08:23 PM

Or maybe a short chamber? [IMG]

[/IMG]The primers shows pressure signs cause by a short chamber in 45 acp, 1911 type firearm. As the action opens the high primer gets primer wipe. A gun smith corrected the chamber problem with a reamer. Not sure i buy this as the cartridge headspaces on the case mouth. Not sure how it could build pressure this way as the bullet is not trapped/ crimped into the chamber like a bottle neck round in a bold action rifle. The 45acp short chamber would hold the action open a tiny amount but still fire if the disconnector was not activated. A bulge might appear near the head if pressure was high. Very Strange.

January 21, 2013, 07:50 PM	#1
Sgt Pepper Senior Member Join Date: August 19, 2001 Location: Texas Posts: 811	Casing issue at primer What issue is indicated by the condition of the primer area of these casings? Thanks.

January 21, 2013, 08:03 PM	#3
243winxb Senior Member Join Date: July 26, 2011 Location: USA Posts: 1,730	High Pressure with Primer Wipe "Primer wipe" is a teardrop-shaped firing pin impression, accompanied by a drag mark (scratch or gouge) following the "point" of the teardrop and leading away from the primer, sometimes into the brass. This is because the firing pin does not fully retract after the round has fired and the slide is traveling back during ejection, causing the case to drag across the firing pin as it is thrown clear. It is not in any way harmful, except sometimes to the case if the primer pocket edge is gouged. Kahr will tell you it is a normal condition for their pistols, even saying so in the owner's manual. [IMG][/IMG] click for larger photo. Last edited by 243winxb; January 21, 2013 at 08:23 PM.

January 21, 2013, 08:23 PM	#4
243winxb Senior Member Join Date: July 26, 2011 Location: USA Posts: 1,730	45 acp Short Chamber Or maybe a short chamber? [IMG][/IMG]The primers shows pressure signs cause by a short chamber in 45 acp, 1911 type firearm. As the action opens the high primer gets primer wipe. A gun smith corrected the chamber problem with a reamer. Not sure i buy this as the cartridge headspaces on the case mouth. Not sure how it could build pressure this way as the bullet is not trapped/ crimped into the chamber like a bottle neck round in a bold action rifle. The 45acp short chamber would hold the action open a tiny amount but still fire if the disconnector was not activated. A bulge might appear near the head if pressure was high. Very Strange.

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January 21, 2013, 08:00 PM	#2
wncchester Senior Member Join Date: December 1, 2002 Posts: 2,832	Nothing. Your firing pin hits are a bit erratic in depth and that suggests some of your cases may be a bit short but if they fire they're fine. ??