Rebounding locks ??

[Tom]

Hi
I have been reading about parker actions and they mentioned but did not elaborate on rebounding locks. They say this holds the hammer back after it has fired, in order to keep it out of the indentation of the primer. This is a cool idea.That naturally brings up all sorts of questions in my head.

Is this rebounding lock only on hammer guns or hammer less or both ?

Here's why I ask, I have just set my barrels back .004 to tighten up the face. I am very pleased with the results, so far I have shot six rounds of skeet with it and am always checking the gun out to make sure it looks ok. Upon examination the right hammer indents the primer pretty deep, quite a bit more than the left. My friend suggested file down the right pin a little before it pokes a hole in a primer. Needless to say I'm a little hesitant to just go filing away.
If I put a feeler gauge on the breach face both pins protrude the exact same amount after pulling the triggers of course.

So now I'm thinking are they being held back by a rebounding catch and when fired they actually stick out further before being held back ?

Setting the barrels back shouldn't effect the depth of the hammer mark if they are set back to where they left the factory. The more I think this over the more questions I have.
Can anyone shed some light on this ??
Thank you for any info, Tom