Rebounding locks ??

[B. Dudley]

The first couple thousand hammer guns had non-rebounding hammers. They would have hammers which had a "half cock" safe position that the hammers had to be pulled back to before the gun could be opened with fired shells in it, or before loading the gun with new shells.
Hammer guns with rebounding locks do not have a locked "safe" position that you can pull back to. Instead, the hammers pop back to the "safe" position automatically and you must pull up on the trigger to be able to push the hammer forward.

The same goes for the hammerless guns too. The very first ones had non-rebounding hammers. Then they rebounded and did until the end of Parker production. The hammers in hammerless guns ease up just a hair after firing. That way they do not stick in primers.

Sounds to me like your issue is a non issue. Unless you are having misfires, or pins sticking in primers. There is no trouble. The fact that your one pin is hitting harder than the other may just be wear to the pin. If it is not sticking or puncturing the primer, you are ok.