I got recommendations on how to go about adjusting the trigger pull and believe the recommendations were all appropriate. The recommendations included polishing and spring force adjusting (Cutting).
I decided that I should have an understanding of what influences how much trigger pull force is required to release the hammer on a typical lever rifle. There are several components I identified that influence trigger pull. My interpretation is a simple analysis. I am sure that another analysis could be performed to provide a much greater analysis than mine.
Here are my thoughts:
- A] Hammer and Trigger engagement angle are critical (Lets assume that the engagements are optimized at a perfect 90 degrees).
- B] Actual static friction between the hammer and trigger sear influenced by material, surface smoothness, and trigger-sear engagement pressure from the hammer spring.
[INDENT]D] Trigger return spring back pressure [/INDENT]
Simplistically stated, total trigger pull force equals the total added forces of B+C+D.
All of these act in the same direction (opposite trigger pull) when attempting to pull the trigger.
Items B and C tend to be predominantly friction based, but item D is all spring pressure based.
Items B and C are the most difficult to correctly modify, therefore my efforts focussed on item D.
To determine how much of a contribution the trigger return spring was adding, I used a precision trigger weight set and measured the trigger return spring force. (Required me to hold the hammer back from engaging the sear).
Finding was that the trigger spring contributed aproximately 2 Lbs of force, therefore, reducing the force of the trigger spring to 1 Lb, should correspondingly reduce the overall trigger pull by 1 Lb.
In a week or so, I plan to check my calculations by installing a different trigger return spring.
Bob Nisbet
