touch hole liner,50cal gpr

[renoman]

I have gotten some spare liners from TOTW for my gpr,and Ive double checked the invoice numbers to the website for replacement liners.They would seem to be the right ones (in stainless steel).
the trouble is they wont screw in flush with the barrel.Its like the screw cap part is slightly to big,altho checking by eye against the stock one everything looks the same.
Do you have to tweak these parts or did I order the wrong size?Eventho they look the same.

 

[renoman]

Well,Ive turned the head down and shortened the new liner so it is a few thousands smaller than the stock one (witch screws in no prob) and it still wont go in farenough to flush up with the barrel.Odd.
Any ideas?,thanx, Keith.
P.S. I ordered two new liners,they are both the same fit,stock one fits great still.

 

[Hunter66]

Take a look at the angle and how it is hitting the barrel. It sounds as though the angle on the liner does not match the angle of the chamfer in the barrel. I ran a 1/4"x28 tap through mine to convert the threads from metric and then any TC liner would fit it. The pitch of the two different threads is so close (.006 of an inch) that you can do that and get away with it. You could also try getting liners from RMC Sports and see how they fit. They sell the factory Lyman ones I believe.

 

[CoyoteJoe]

Take a look at the angle and how it is hitting the barrel. It sounds as though the angle on the liner does not match the angle of the chamfer in the barrel. I ran a 1/4"x28 tap through mine to convert the threads from metric and then any TC liner would fit it. The pitch of the two different threads is so close (.006 of an inch) that you can do that and get away with it. You could also try getting liners from RMC Sports and see how they fit. They sell the factory Lyman ones I believe.

I'd really not advise doing that. :nono: The metric thread, 6x.75mm, is really closer to 33 threads per inch and when tapped to 1/4x28 only the first two threads are at all good, the rest being mangled. Such a rethread job may look OK but the metal has been displaced and will have very little strength. If I were to retap a 6x.75mm, I might be tempted to try 1/4x32 for the White Lightnin' liner, but really, I'd prefer 5/16x24 to assure I have clean threads full depth.

 

[FPDoc]

I've got several questions with regard to my new GPR .54 Flint

TOTW bronze or Stainless touch-hole-liner (ampco?)when replacing, or other recommendations?

What about opening or relieving outside in as well as the relieved inner portion?

What about "parabolic" relief of liner or best simulation by hand?

Finally (sort of) the liner on my new GPR is NOT centered front-to-back and is lined up about the back 1/3rd of the pan. Should I widen the pan so it is centered front-to-back?

Finally (for now at least) the frizzen does have a small (visible with cross lighting) gap. Can that be fixed with the "pulling abrasive paper between the 2 pieces trick" or disassemble and stone or how is that best addressed?

Any advise on these points or any one of them will be most appreciated.

Thanks guys,
SteveB

 

[Birddog6]

:nono: I don't advise that either... You may have gotten it to thread in but you cut out half of the threads when you did so & what is left I would not trust it to shoot. Way too much chance of it blowing the vent liner out & hurting yourself or a innocent bystander.. :hmm:

 

[Birddog6]

Easiest thing to do is just drill & cone the existing vent liner inside & out & use it. As far as the vent liner not being centered ? would be better if it was forward of center rather than back of it, however you may not notice a dif. I would try it out with a modified vent liner & see how it does. They always worked for me.

As for the pan, if I was to mess with it I would use a file or leave it alone. Sanding it usually caused edges to be rounded & not where ya usually want them rounded. A slight gap will not effect the lock function. If it is a minor gap I would let it alone.

95% of the time when I see a guys at the range having trouble with a GPR or T/C flintlock, it is from being inexperienced with a flintlocks in general, not a rifle or lock problem. And unfortunately when they have these problems they sometimes want to modify this & that & change locks & etc., and all they need is some time with a experienced flintlock shooter & most things will iron themselves out with some shooting time. Every rifle has it's quirks & it is up to the individual to learn how to handle same quirks. I am not saying this is applicable in this particular instance, but something to think about.

The only consistant problem I have seen with a GPR is the existing vent needs to be modified a tad. The only consistant thing I have seen with the T/C's is to have the lock upgraded (it is Free from T/C) and install one of their new vent liners & it also will perfor remarkably well..

:thumbsup:

 

[FPDoc]

Thanks Birddog,

Good advice. It won't hurt to use the gpr pretty much as is for a while and see how it goes. I like the way it shoulders and settles offhand. The sights agree with me and for a production gun it's not bad looking.

Thanks,

SteveB

 

[FPDoc]

Any thoughts regarding SS vs Ampco (bronze?) TH liners? and is it worth/advisable to drill/rethread an Investarms bbl for the Chambers parabolic TH liner. I don't think they come in the metric size do they? or is that another "see if the easier changes work" things?

 

[CoyoteJoe]

There is only so much a vent liner can do. An inside cone helps bring the main charge closer to the prime, and that obviously does help speed of ignition. A slight cone on the outside seems to help funnel the flash into the vent and improves reliability of ignition.
One reason I don't care for the White Lightnin' vent liners is that when installed and cut as per instruction, you can't add an outside cone without running into the inside cone and making the vent too large. Also the odd-ball 32 threads per inch means that once you tap for it you are stuck with it. Any liner with a 5/64" vent and cone on inside and outside works as well as any other. I've made several from socket head set screws and they also work as well as anything else.
As to Ampco or stainless, I don't know which would last longer, I've never burned out a liner, perhaps because I mostly shoot light loads and reserve the heavy powder charges for sight-in and actual hunting. I have found the Ampco liners with screwdriver slot tend to burr-out the slot rather easily. I like the stainless allen head liners with the inside cone deepened a bit, the allen socket acting as an outside cone.

 

[FPDoc]

I sure appreciate your input with this.
thanks