Bill Calfee
Gun Fool
Wear patterns, continued...
CYA friends:
Man I'm having a refresher course on the complexities of SAP ignition.............no wonder MD-PAS ignition dominates like it does.
Anyway...if you look at this picture, and the arrows, they point to a critical wear pattern, "read drag" in the SAP system.
This wear pattern varies depending on the number of times the action has been cycled, fired, which of course I can have no idea about...
But, I do have an indicator of the number of times these firing pins were cycled, that being the primer burn ring in the nose of the breech bolt.
And the best I can tell, visually, is that the more pronounced the primer burn ring is in the bolt nose, the deeper the wear pattern on the firing pin.....indicating the number of times the action was cycled and fired.
This is not fool proof, but, it's got to be close...
For example, the third pin from the left came from the bolt out of an unfired action.....it has no wear pattern...
The red arrow indicates just enough primer ring to show the action was fired some small number of rounds...
The black arrows indicate varying degrees of primer ring decay in the bolt noses...likewise the number of times the action was fired.
_______________________
Oh, oh, think 19.....................
Your friend, bc
_________________________
_________________________
PS:
Please look closely at the third pin from the left, in the picture.....it came from a new, unfired action.....it has absolutely no wear pattern on the firing pin.....
____________________________
CYA friends:
Man I'm having a refresher course on the complexities of SAP ignition.............no wonder MD-PAS ignition dominates like it does.
Anyway...if you look at this picture, and the arrows, they point to a critical wear pattern, "read drag" in the SAP system.
This wear pattern varies depending on the number of times the action has been cycled, fired, which of course I can have no idea about...
But, I do have an indicator of the number of times these firing pins were cycled, that being the primer burn ring in the nose of the breech bolt.
And the best I can tell, visually, is that the more pronounced the primer burn ring is in the bolt nose, the deeper the wear pattern on the firing pin.....indicating the number of times the action was cycled and fired.
This is not fool proof, but, it's got to be close...
For example, the third pin from the left came from the bolt out of an unfired action.....it has no wear pattern...
The red arrow indicates just enough primer ring to show the action was fired some small number of rounds...
The black arrows indicate varying degrees of primer ring decay in the bolt noses...likewise the number of times the action was fired.
_______________________
Oh, oh, think 19.....................
Your friend, bc
_________________________
_________________________
PS:
Please look closely at the third pin from the left, in the picture.....it came from a new, unfired action.....it has absolutely no wear pattern on the firing pin.....
____________________________
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