I purchased a hammer strut and spring from Winchester with plans to eliminate the rebounding hammer on my Miroku 1892 but I've since sold the rifle. If anyone wants the strut and spring, I'll give them to you for the shipping cost.
Send text to 406-304-1462

Parts are spoken for. You snooze, you lose!

Dennis
I have also done a couple of 1892 Japchesters and an 1886.
On the 1892 models they both had flat trigger return springs. Removing , heating with a torch and flattening them made a huge difference.
On your rifle(s) hold the hammer all the way back with your thumb and pull the trigger. What you are feeling is just the trigger return spring.
Hopefully this helps you or someone else.

David

Thank you David for the info.

Dennis