Frizzen Bounce-back

[Bob Gerard]

I was checking on one of my pistols and sparking it, and at first thought the frizzen wasn’t opening all the way, so I put a drop of oil on the frizzen heel at the feather spring.
Then I remembered about frizzen bounce back and it took a slow motion video to discover that’s what is happening.
No concerns really , except that it might chip my flints or break them.
Have folks here tried to correct this area of lock performance or just leave it be?
Below are two shots showing (first) the frizzen opened and (second) the bounce back.
Ps., this is one of those old small Siler locks from 40 years ago where the half-cock position is really far forward)

[Daryl]

Appears the frizzen base is hitting the flint back near the stop jaw, which should not break the flint. If the flint was shorter, that might happen.

[Steeltrap]

I had the same bounce back issue with an L&R awhile back. When I removed the lock and held it in my hand, it worked fine and the frizzen stayed open. But when I installed it, the frizzen would close. The reason for that is because your hand "gives" just enough to keep the frizzen open. When you have it installed on the gun, there is no movement so the energy allows the frizzen to bounce back.

This happens so fast you cannot see it with your eye. I stumbled on the bounce back as I had my thumb positioned in front of the frizzen. I pulled the trigger and my thumb got whacked from the frizzen opening.

You are getting pretty decent spark. The series of pic's below were my lock. As you can see sparks did happen....but not the shower I wanted for consistent ignition.

The fix for the bounce back was a stronger frizzen spring. Not only does it hold the cover open, but it's just a bit more resistance for the flint to scrape the frizzen face.

Should you want to get rid of the bounce, likely a new spring is in order.

[Bob Gerard]

Thanks Steeltrap. I was wondering if a stronger frizzen spring was a solution. (It sparks much more  if I adjusted the flint but the sparks would obscure the details of the frizzen bounce.)
My concern mainly is with damage to the flint. They are not cheap any more!

[Steeltrap]

Well, I'm not a lock expert by any stretch. But I've read a lot about lock geometry and everything I've read states that when the hammer is in the "rest" position, if you draw a line at the top of the lower jaw, the line should point\extend to the front of the powder pan.

The lock below is a Dixie lock that had a wonky hammer position. So, i had an L&R hammer in my parts stuff. I replaced the Dixie hammer with the L&R (the pic below is that in the "roughing out" stage) hammer to get that geometry in the pic below. Now, Ideally that line should point a little lower to hit the pan.....but I left it like that to see how it would perform. It sparks very well and flint life seems good. So, I'm not changing the hammer angle.

I did change a hammer angle on another build. It wasn't necessary to heat it first as the vice bent it easy. The only caution there is if you don't anneal it, the metal may crack if you're moving the angle a lot. 

I tossed in that second pic (not my pic\work) just for additional information.