rebuild vent liner?

[ffffg]

the vent liner on my pedersoli mortimer is sloted for a screw driver.. i recently deepened the pan to just below the flash hole to get it to stop gas cutting into the pan.. it always has and still is a very good ignighter, and fires instantly.. but to stop the gas cutting into the lock body just below the pan on the last outing i glued some super glue in the slot before about a 30 round trap session.. it looked like it pretty much stoped the gas cutting but will need to be redone each outing.. i just put in some accuglass without release agent and will see how it holds next time out.. i suppose i could have a local smith fill the lower part of the slot in with brazing.. i am considering putting in a white lighning vent liner but it has a patent breach.. in your estimation will one of the the chambers white lighting vents work in a patent breach? (more of pedersoli mortimer in next post about the lock problems) dave

 

[Mike Brooks]

Should work great .

 

[Birddog6]

My experience of one gas cutting the pan turned out to be because the vent liner slot pointed at the bottom of the pan. Using a different liner brought the vent liner slots parallel with the top of the pan & that stopped the gas cutting.

First try several vent liners, once in a while the threads start dif on them thus the screwdriver slots end up in a dif position.

IF that don't work, your sloted liner should have a beveled seat at the top edge. You can take a 82 deg countersink & just put it in the hole & hand turn it & slightly deepen this bevel for the sear. Then try the liner. Won't take much at all to bring the slot to parallel with the barrel. Take the bevel down til the vent liner just barely is not parallel, then a slight lil snug with a screwdriver will bring it to parallel.

Also if the vent is Below the top of the pan, I would go with a different liner, most likely a Ampco non sloted one & file it flush & cone it on both sides. Even tho I like the Chambers liners the best, in a patent breech I would want one I can get dif. types of liners for that are the same threads, as once ya change to the Chambers ya are stuck with that thread. You may want to try a new T/C liner in it, as they work pretty good for a removable liner also & should stop the gas cutting, if you are using a 1/4 x28 thread vent liner. If you are using metric vent liners, your options are minimal without going to a larger liner.
Do NOT try to go from a ? Lyman size MM thread liner to a 1/4 x 28 thread or a 1/4 x 32 thread. Not enough meat there for full clean threads. I don't know what a Pedersoli uses but thought I should mention that.