Touch hole liner fit

[mbarnes0905]

I recently replace my lyman deerstalker touch hole liner with a rmc liner. When I screw it in tight, it seems to go too far in and is not flush with the barrel. Should I back it out a little to make it flush with barrel or leave it tight? Thanks for any advice

 

[longcruise]

Flush with the inside or outside?

 

[Ames]

For too long a length: You file off some of the inside length. Drill and tap a hole in a scrap of metal. Thread the liner into the scrap and file down some of what protrudes too far into the barrel. Fit and check it with the liner screwed all the way down in the barrel again.
You may have to do it a couple of times, sneaking up on the finished length until it no longer catches your jag.
For too short a length: I'd buy a longer liner.

 

[Grenadier1758]

I agree with @Ames. @mbarnes0905 should not have any of the liner protruding into the barrel's bore. Now we need to know the answer to the question of whether the liner is protruding into the bore or if when tightened, the face of the liner is below the barrel flat.

 

[TreeMan]

I do believe he is saying that when he screws it in tight it sets a bit in the barrel too far from the outside. I have several that do this with an RMC liner. I simply unscrew it just a tad so it’s flush with the outside of the barrel. It’s normally no more than 1/4 of a thread.

 

[Ames]

And goop the threads with Anti-seize.

 

[mbarnes0905]

Yes, what treeMan said. When I tighten it down, I does not catch my jag so it maybe flush on the inside but sits in deep on the outside. I have to back it out 2 full turns with Allen key to make it flush with the outside of barrel

 

[Timber Wolf]

I may be over thinking this, but if it is in less than a full thread I say leave it tight. That way all the thread “bottoms” are protected and I don’t see how it could cause any issues. Backing it out flush may look better, and may bring the charge incrementally closer to the primer flash but may also expose threads inside. Issues with erosion or just fouling build up inside may prevent fully seating an appropriately sized touch hole liner later. I am a little surprised you have this issue. I replaced the factory liner on my Lyman GPR with an RMC and it fits perfectly.

 

[2 shots]

dont want threads in bore for many reasons, main one is when they corrode in the chamber will likely strip out the threads when trying to remove

 

[deerstalkert]

you want the liner flush against the lock bolster, flush to the face of the barrel flat. if it makes a recess it will corrode the outer threads each time the primer burns.

 

[TDM]

As said you want the liner tight and flush with the barrel. My vote is also to find a longer liner. A longer one can always be filed down for a good fit.

 

[EC121]

Sounds like one of those set screw liners. Look for a liner with a shoulder to hit the countersink on the barrel flat.

 

[M. De Land]

I recently replace my lyman deerstalker touch hole liner with a rmc liner. When I screw it in tight, it seems to go too far in and is not flush with the barrel. Should I back it out a little to make it flush with barrel or leave it tight? Thanks for any advice

The best method I have come up with having machined and installing my own liners is to fit them full depth than contour the inside to the groove diameter of the barrel interior, reamed free of rifling a half inch in front of the flat breech plug face. This method leaves no corners or threads exposed to catch fouling or cleaning patches as the liner interior is the same profile as the reamed bore fit flush on the curve.
The exterior is also made flush with the barrel flat and cupped toward the interior thus directing/vectoring pan flash inward and discouraging interior pressure outward.
Sort of "white lightning" in reverse design. The one I have in my SMR currently is made of A-2 high chrome tool steel left annealed so it could easily be removed and replaced should it erode faster than if hardened. I will be testing how long it lasts and if necessary will harden it's replacement.
I believe flash hole lining at the build is a modern concept as original flash holes seem to meerly be drilled holes through the barrel wall intially.