Need Id Advice and more, TC Penn Hunter

Got this TC Penn Hunter in an estate sale. Here is what I know about it. The fellow who owned it shot it in "competition". He converted, i.e., replaced the original single trigger to a double set trigger. Don't want to be too critical here but the workmanship after conversion was not what it could have been. I got rid of the double trigger and installed an original type single trigger for this model of TC. He had replaced the lock, whatever that might have been, with a L&R flintlock. So don't know if it originally was a cap gun or flinter.

My questions are:
1. What is the small screw on top of barrel at the breech end? I should say what is its purpose. I have not tried to remove it. Pic below.
2. How can I tell if this rifle was a cap gun originally. Just curious I suppose.
3. Not pictured is the vent hole which is a bit too high over the pan from where it should be. Thus the pic of the non indexed barrel/breech plug. (maybe the breech plug is not the original). My understanding is that the TC Penn Hunter came it both cap and flintlock, so was the breech plug the same on both of these? Or maybe the small screw on the barrel is the answer to that?

Finally is does shoot. I'm replacing the vent liner with a new one as the hole was drilled out way too big. Maybe to get better ignition because the vent hole/liner was too high and maybe that is because the barrel/breech is not indexed all that well. You experts could answer that.
Oh, and the breech end of barrel sits about .125" from barrel channel. Not bedded either.
Just trying to correct some of these issues.
Thanks,
Marlowe

If your vent is too high, drop the barrel and tang until the barrel bottoms out in the channel or inlet your barrel even lower, you may have to file the underlugs slightly to get your barrel wedges in easily.

The L&R lock is a step up from a TC lock, it isn't a drop in to replace a TC lock with a coil main spring. I put an L&R flintlock in a percussion TC stock, it took some work to get it to fit.

I have seen that top screw before but don't know what it is for.

A percussion breech plug is completely different than a flint breech plug, the percussion breech plug has the cast snail on top for the nipple to screw in.



TC Renegade with an L&R lock, different breech plug. The snail is part of the lock and not cast on the breech plug

Eric Krewson said:

If your vent is too high, drop the barrel and tang until the barrel bottoms out in the channel or inlet your barrel even lower, you may have to file the underlugs slightly to get your barrel wedges in easily.

The L&R lock is a step up from a TC lock, it isn't a drop in to replace a TC lock with a coil main spring. I put an L&R flintlock in a percussion TC stock, it took some work to get it to fit.

I have seen that top screw before but don't know what it is for.

A percussion breech plug is completely different than a flint breech plug, the percussion breech plug has the cast snail on top for the nipple to screw in.

View attachment 356737

TC Renegade with an L&R lock, different breech plug. The snail is part of the lock and not cast on the breech plug

View attachment 356753

Click to expand...

Thanks Eric. The small screw just makes a hole in the breech plug. Maybe some kind of a index hole for barrel making or plug alignment. I did a prussian blue test on the bottom of barrel where the channel is. Not one trace of bluing touched channel except where end of stock is. Tang breech plug needs to drop about .062". So will remove some wood where tang lays. That will drop the vent hole about rights. Pic will show some embedding where tang is. That of course raised it as well. Pics to show. Thanks, Marlowe

Screw is blanking screw for a rear scope mount.

I had a problem with the lock bolt position between the TC lock and the L&R lock, you may have to notch the breech plug to accommodate the lock bolt as you drop the barrel. Whoever inletted for your L&R did a sloppy job, you might black the inside of the lock and see if anything is hitting wood. I removed a lot of wood in the TC lock inlet to accommodate the L&R internals, especially the mainspring.

I had to redrill the lock bolt hole to hit the blind socket on the bridal of the L&R lock, the new hole was off from the TC position, I removed some of the breech plug to keep the barrel off the lock bolt.

Check and see if your lock bolt is holding the barrel up, if it is you can notch the breech plug to accommodate it.