Replacing Vent Liner.

[mahd776]

I am working on a older Investarms flintlock rifle. At some point in its history someone replaced the vent liner with a homemade one. Looks like cut off screw with a hole drilled for the vent. Was not coned on the breech side just a drilled hole and not a very straight hole at that. Replacing with a Lyman factory vent liner I have on hand but I have a question.

If I screw the new liner down flush with the outside of the barrel it protruded into the breech a bit. If I install with the liner a bit proud of the outside of barrel it does not protrude into the breech. Looking at my Lyman GPR the vent liner is a bit proud of the barrel. Guessing no protrusion into breech is preferred to keep from snagging cleaning patches. Correct?

An option I suppose is to mount flush with outside of barrel and grind the liner a bit shorter on breech inside end of liner.

Thanks for advise!

 

[Ames]

Yep. You answered your own question there. Grind a bit off the inside end of the liner.

 

[Grenadier1758]

Looks as if you have decided to do what Ames and I would have told you.

 

[Zonie]

IMO, the liner should not stand proud of the outside of the barrel and it should not stick out into the bore. It should be filed down to a length that matches the thickness of the barrel wall at the breech.

A lot of the vent liners sold by places like Dixie and TOTW are intentionally made longer than the barrel wall is thick. That allows each liner to be custom fit to the barrel.

One of the better ways to shorten the liner is to buy a hex nut that has the same thread size as the liner. Use a hack saw to cut thru one wall of the nut and screw the liner into it. Screw the liner in or out of the nut so that the amount of material that needs to be removed is sticking out of one side of the nut.
Then use some locking pliers like Vise Grips or a regular vise to clamp on the outside of the nut with the "extra material" side of the nut pointed up. This will lock the liner in place and give a good reference point to stop the filing.

Now, using a flat file, file off the excess material until the file meets the face of the nut.
Unclamp the nut and screw the liner out so that a little of the filed end is sticking out above the face of the nut and reclamp the nut.
Use the file to chamfer or break the sharp edges on the liner and it is ready to be installed.

 

[mahd776]

Thanks everyone. Excellent instructions Zonie!