Lyman GPR flint breaking

[pmihalevich]

Out shooting the New Rifle yesterday, and after 4 shots the flint needed replaced, then another few shots replaced again.
Replaced 4 flint in 25 rounds.
Has anyone else had this problem, does the lock itself on the gpr have a problem.
Flint was stricking the fizzle mainly left to center, nothing right of center.
Is there a certain size I should be using, the flint I was using was chipping at the end and seemed a little large for the gun.
Thanks

 

[Bnewberry]

Pictures would help. There is a bit of art and science to making a flintlock work well. You definitely need the right sized flint.
1. When the lock is in the fired position you want the edge of the flint pointing in the center of the pan.
2. You want the edge of the flint to contact across the width of the frizzen.
3. You don’t want the edge of the flint to hit the frizzen straight on. Rather it should be more of a glancing strike to scrape down the length of the frizzen.
4. You don’t want your frizzen to bounce away from the flint and then return to hit the flint. This breaks flints and is sometimes evidenced by two scrapes shown on the frizzen with a gap between them.

 

[Gonetocamp]

Out shooting the New Rifle yesterday, and after 4 shots the flint needed replaced, then another few shots replaced again.
Replaced 4 flint in 25 rounds.
Has anyone else had this problem, does the lock itself on the gpr have a problem.
Flint was stricking the fizzle mainly left to center, nothing right of center.
Is there a certain size I should be using, the flint I was using was chipping at the end and seemed a little large for the gun.
Thanks

GPR typically takes a 5/8" x 3/4" flint.

 

[HSmithTX]

I found it easiest to set the flint up a half cock, get the flint end square with the frizzen and turn the flint bevel up or down to get it to contact the frizzen above center. Then back it off the closed frizzen 1/8” or so and tighten it making sure it stays square to the frizzen, and be sure it isn’t going to swipe the side of the barrel when it falls. If it still breaks flints you probably have an issue with the frizzen sticking or not opening smoothly. Mine opens with about 40% or less of the force it takes to cock and flints last a good long time for me. Make sure it’s smooth and not overly heavy opening the frizzen and get the flint set up well and try again.

 

[pmihalevich]

I found it easiest to set the flint up a half cock, get the flint end square with the frizzen and turn the flint bevel up or down to get it to contact the frizzen above center. Then back it off the closed frizzen 1/8” or so and tighten it making sure it stays square to the frizzen, and be sure it isn’t going to swipe the side of the barrel when it falls. If it still breaks flints you probably have an issue with the frizzen sticking or not opening smoothly. Mine opens with about 40% or less of the force it takes to cock and flints last a good long time for me. Make sure it’s smooth and not overly heavy opening the frizzen and get the flint set up well and try again.

Thanks , sounds like some great advice, ill jack with it after while. And post some pics.

 

[pmihalevich]

Pictures would help. There is a bit of art and science to making a flintlock work well. You definitely need the right sized flint.
1. When the lock is in the fired position you want the edge of the flint pointing in the center of the pan.
2. You want the edge of the flint to contact across the width of the frizzen.
3. You don’t want the edge of the flint to hit the frizzen straight on. Rather it should be more of a glancing strike to scrape down the length of the frizzen.
4. You don’t want your frizzen to bounce away from the flint and then return to hit the flint. This breaks flints and is sometimes evidenced by two scrapes shown on the frizzen with a gap between them.

Thank you for some tips, and yes I should have posted some pics, I will soon thanks

 

[Capnball]

Maybe check to see if that little piece of leather is there to pad the flint in the jaw.

 

[Timber Wolf]

I purchase a GPR NIB a couple of years ago. While I have not shot it a great deal I did experience a broken flint while out on a Woods Walk. I chaulked it up to bad luck, replaced it, and went on. I have maybe a hundred shots total on this rifle so with one broken flint can't say there is an issue with the gun.

 

[pmihalevich]

I purchase a GPR NIB a couple of years ago. While I have not shot it a great deal I did experience a broken flint while out on a Woods Walk. I chaulked it up to bad luck, replaced it, and went on. I have maybe a hundred shots total on this rifle so with one broken flint can't say there is an issue with the gun.

I'm thinking it's a flint issue, hopefully.
Gonna start looking for some new flint, I wonder if good ol Missouri Chert is available somewhere. Appreciate the input.

 

[pmihalevich]

Maybe check to see if that little piece of leather is there to pad the flint in the jaw.

I have leather , maybe it's just the flint, the pack I have has all sizes some so thick I can't even use them,

 

[sturmkatze]

I'm thinking it's a flint issue, hopefully.
Gonna start looking for some new flint, I wonder if good ol Missouri Chert is available somewhere. Appreciate the input.

That will eat up your frizzen. Chert works, but I’d plan on a new frizzen after awhile.

 

[deerstalkert]

Flint, Chert, and Jasper:
Names for Microcrystalline Quartz
the geometry between the "flint" and frizzen is the most important.

 

[Barry Strickland]

Go back and read post #2 by Bnewberry
If the flint hits the frizzen to high it is like it is hitting a steel wall instead of scraping down it.
Barry

 

[azsixshooter]

I had problems with my GPR last week because I had a flint that was too small and I had a lot of trouble getting it to spark properly. I found an old thread here in the Flintlocks SubForum and ordered a 12 pack of hand-knapped flints from trackofthewolf.com and some leather wraps. The 3/4x3/4" size was listed as the correct fit for Lyman on that site so I got those. They are working awesome so far. Good luck, it looks like you got a lot of great advice here. I don't think there is anything wrong with the GPR lock but I have seen posts where some guys upgrade them with an offering from L&R. You probably won't need to do that to get your GPR shooting great, but at least an option exists!