closed Frizzen

[TTT]

I am the proud owner of an older custom built .40 cal flintlock rifle. It has an L& R lock in it, and frizzen and pan show sighns of many shots. I have started having issues with the frizzen not opening completely with the fall of the hammer. Still getting great spark but It ends up resting on the hammer. would this be a main spring issue of the hammer or somthing else?
Thanks again!

 

[Bnewberry]

I am no expert but these are Possibilities:

1. Flint is too short or hitting at wrong angle.
2. Bad interface between frizzen and frizzen spring.
3. Weak mainspring.
4. Frizzen spring to strong.

 

[IanH]

Post a photo of the lock at halfcock with the frizzen closed.

 

[Comfortably_Numb]

Lube the frizzen pivot and the shoe where it rubs on the spring.

 

[wiscoaster]

Ditto the above.

 

[dave_person]

Hi,
Before you conclude anything, make sure it really is not opening but rather rebounding back on the flint. Don't fool yourself thinking that you would be able to see that if it was happening. You won't. First, place a piece of masking tape on the frizzen spring where the toe of the frizzen touches it when fully opened. Then close the frizzen and fire the lock (with flint of course). If the tape has a dimple in it, the frizzen is rebounding. If not, it is not opening all the way. If it is rebounding, the frizzen spring may be too weak or the toe of the frizzen is badly worn. To solve that, you may have to anneal the spring, open the bend a little so it exerts more force and then harden and temper it. If the frizzen is truly not opening, then what others have described may solve it.

dave

 

[TTT]

Post a photo of the lock at halfcock with the frizzen closed.

 

[TTT]

Hi,
Before you conclude anything, make sure it really is not opening but rather rebounding back on the flint. Don't fool yourself thinking that you would be able to see that if it was happening. You won't. First, place a piece of masking tape on the frizzen spring where the toe of the frizzen touches it when fully opened. Then close the frizzen and fire the lock (with flint of course). If the tape has a dimple in it, the frizzen is rebounding. If not, it is not opening all the way. If it is rebounding, the frizzen spring may be too weak or the toe of the frizzen is badly worn. To solve that, you may have to anneal the spring, open the bend a little so it exerts more force and then harden and temper it. If the frizzen is truly not opening, then what others have described may solve it.

dave

 

[TTT]

Hi,
Before you conclude anything, make sure it really is not opening but rather rebounding back on the flint. Don't fool yourself thinking that you would be able to see that if it was happening. You won't. First, place a piece of masking tape on the frizzen spring where the toe of the frizzen touches it when fully opened. Then close the frizzen and fire the lock (with flint of course). If the tape has a dimple in it, the frizzen is rebounding. If not, it is not opening all the way. If it is rebounding, the frizzen spring may be too weak or the toe of the frizzen is badly worn. To solve that, you may have to anneal the spring, open the bend a little so it exerts more force and then harden and temper it. If the frizzen is truly not opening, then what others have described may solve it.

dave

yep rebounding. you can see it when you slow the video down.

 

[Bnewberry]

I am no expert but these are Possibilities:

1.
2. Bad interface between frizzen and frizzen spring.
3.
4.

My guesses based on the pictures and video.
Does the frizzen move freely by hand? Does it feel like it takes very little to open and close it by hand?

There should be some resistance.

 

[TTT]

yep rebounding. you can see it when you slow the video down.

OPEN.

 

[dave_person]

Hi TTT,
I repair scores of locks every year and developed a protocol for diagnosing things. One common complaint is yours. The key importance of diagnosing rebound versus incomplete opening is the solutions are 180 degrees apart. You must strengthen the resistance with which the frizzen opens not make it less. A good rule of thumb is that the force needed to open the frizzen (measured with a luggage scale or trigger pull scale) should be 30% of the peak force needed to pull the flint cock back from full rest to full cock. That is a good starting point.

dave

 

[IanH]

I would also flip the flint over, bevel up, for your particular lock's geometry. Bevel down makes the flint edge hit too high on the frizzen, throwing it open early in the sequence and exacerbating the problem Dave describes. I like 2/3 up the frizzen face to be my initial point of contact, some locks like more or less. You could also run a shorter or more worn flint bevel up.

 

[rickpa]

I had trouble with an L&R late English lock doing the same thing i.e. rebounding frizzen. I sent it back to them. Turns out they changed the frizzen spring after I had bought it. They replaced the old one with the new that had a longer to leaf at no charge. This was back in the 90s IIRC. You might try contacting them first.

 

[TrophyGuy]

Easy way to diagnose a rebounding frizzen is to simply position your thumb near the end of its travel to see if it is struck by a full arc swing. It might sting a bit but you only need do it a couple of times to determine full opening. If the frizzen still ends up resting against the flint after a normal firing you have rebound and didn't need high speed cameras or taping schemes to diagnose. That's how I found mine and a simple frizzen spring replacement solved the problem. Measuring frizzen spring constant would require setting up a fixture test rig. Cheaper to simply change it out. Pick low hanging fruit first.

 

[sportster73hp]

Video definitely shows rebound. Slo mo on cell phones are great.