If your getting marks on the frizzen and breaking flint the most likely issue is the angle of hammer approach to the frizzen. You may be able to change it a little by flipping the flint the other way; otherwise heat and change the hammer approach. The lock should be balanced to spring strength and approach and a good lock smith could get it sorted out in short order. Maybe not something you wish to tinker with yourself. A coil spring can be shortened and leaf springs can be narrowed to reduce spring power. By balance I mean that speed, frizzen throw, hammer approach, frizzen wear/spark is all optimized.
yep a heavy spring isn’t the factor here IMO .
its poor lock geometry .
Also sounds like a soft frizzen with a frizzen spring that’s not properly match .
Not un common on production guns
Like was said . Try flipping the flint . The other thing you can do is notch out the back of the flint so that it sets a little farther back in the jaws
If you have not done it , I would also polish up the workings of the lock / specifically any [place that metal runs on metal IE the sear to tumbler , main spring to tumbler . Main spring to lock plate . Tumbler to lock plat . Tumbler to bridle . don’t forget the toe of the frizzen , where it rides on the frizzen spring or where the frizzen rides in its bridle . Without the frizzen spring , the frizzen should easily and smoothly flop . Not kinda flop , it should simply fall back
Again most of the time the issue is not a heavy frizzen spring but bad geometry . Especially concerning eating flints
As to trigger pull / this depends on the company .
Many years back CVA and traditions went to a negative cut full cock , over the neutral full cock notch .
This was for liability reasons . Just like Lyman did a few years back when they placed a shorter screw in their double set trigger s
Basically what happens with the negative cut notch is that when the shooter pulls the trigger . They are basically using the trigger to cock the lock a little farther back before the lock will trip .
You can see this if you cock your lock and then slowly squeeze the trigger . If the cock moves back before it falls . Then that s the reason for your heavy trigger pull . When you pull the trigger , you actually have to overcome the main spring .
The only way to correct this is to change the geometry of the full cock notch .
If you do that , be very careful not to go to neutral or you will end up with something that will easily trip when you don’t want it to
Also when your polishing up your lock , don’t forget to polish the sear arm where the trigger contacts it .
Now if the case is that the tumble isn’t a negative . Then the issue also often is that the trigger itself isn’t drilled proper .
All the trigger is leverage . Think of a teeter-totter.
On most production guns , the leverage is equal or heavy in on the sear side .
But if you move that pivot point so that the sear arm comes in contact closer to the pivot , while at the same time your finger is farther from the pivot . Then you get a lighter trigger pull .
Doing this you actually can tune a single trigger to a very light pull even if the main spring is a giant