Vent Liner Location

[Iron Jim Rackham]

I'd like to install a vent liner in a flintlock, but am concerned the breech ply will interfere with it's installation. Will I have ignition issues if I nick the side of the breechplug? Would it create a dangerous condition if I drill into the breechplug? Thanks

 

[Griz44Mag]

I'd like to install a vent liner in a flintlock, but am concerned the breech ply will interfere with it's installation. Will I have ignition issues if I nick the side of the breechplug? Would it create a dangerous condition if I drill into the breechplug? Thanks

Pictures would help -
The breechplug is where most bolsters and flash holes are oriented. You want to ignite the charge close to the base of the charge.
The hole itself needs to be aligned with the center of the pan just above the powder line and below the top of the frizzen cover.

 

[Griz44Mag]

 

[EC121]

If you can, drill the hole half the diameter of the liner plus maybe 1/64" from the plug face. That should clear the plug face. If the lock is already located, try to locate the hole as close as you can to the sunset position in the pan. If you nick the threads it isn't a big deal. If losing that little bit of thread makes the rifle dangerous, you probably shouldn't shoot it at all. I centerpunch a spot on the side flat where I want the hole then inlet the lock to that spot. Then drill the hole for the liner. That leaves a little wiggle room. Sometimes the lock inlet will move if you don't inlet it evenly.
Some folks drill into the plug face to try to get the pan fence to be even with the end of the barrel. I don't worry about getting it even. With today's 5/8" plug lengths it is hard to do.

 

[Sidney Smith]

Insert a dowel into your barrel until it rests on the face of the breech plug. Mark the rod at the muzzle. Now remove the rod, measure the distance from your mark on the rod, to the end of the rod. Take this measurement and measure from the muzzle back to the breech. Mark the barrel at the breech. This will the show you where the face of the breech plug is. You can then inlet your lock so the pan sits just in front of this mark.

Now install your lock, draw a line along the front and back flat of the pan, and down into the pan so you end up with two small straight lines, and a U shape where the pan is. Take a different color marker and now draw another straight line across the top of the pan line using the two straight lines as a guide. Punch the middle of the line that spans the pan. Drill, tap and insert your vent liner in this spot. If done properly you will have your vent hole centered just above the pan, in line with the flats of the pan, the so called sunset position.

 

[Iron Jim Rackham]

Thank you all. I'm simply looking to install a liner in a gun with a worn out, direct drilled touch hole that is a hair's width away from the breechplug. Sounds like it's not an issue, if I drill through a portion of the breech plug to install the liner.

 

[EC121]

If the touch hole is worn out, you don't seem to have much choice. You might put a blank liner in that is set right up to the plug and then drill a regular touch hole. A good grade 1/4x 28 bolt(one long enough to have a shank) screwed in to the shoulder of the bolt threads would work. It could even be coned a bit on the inside.

 

[Griz44Mag]

If the touch hole is worn out, you don't seem to have much choice. You might put a blank liner in that is set right up to the plug and then drill a regular touch hole. A good grade 1/4x 28 bolt(one long enough to have a shank) screwed in to the shoulder of the bolt threads would work. It could even be coned a bit on the inside.

My last one I had to make I used a allen socket set screw. Just ground it off some on top and bottom - then drilled a 1/16" hole in the middle. Having an allen recess in the darn thing makes removing to clean a snap. An factory liner with the allen socket is available from OX-YOKE if you stick with common thread type. Go with the smallest one you can find so will have the option to replace with a bigger one later on in the service life of the gun if needed. Install with teflon taper or anti seize. You will hear a scream here that says to NEVER remove a liner and another faction that says YES to clean - , but I do every few range trips to do a very complete cleaning job. And someday you may decide the hole is getting worn again and want to replace it - so that makes it even easier to service.

 

[Sidney Smith]

Thank you all. I'm simply looking to install a liner in a gun with a worn out, direct drilled touch hole that is a hair's width away from the breechplug. Sounds like it's not an issue, if I drill through a portion of the breech plug to install the liner.

If you drill the touch hole and it touches the breech plug, all is not lost. Remove the breech plug and file a V shaped notch in the plug where it meets the touch hole, and forward toward where the powder charge will sit. This will allow powder to settle in this notch and will allow a slightly rearward facing touch hole to still ignite the charge. There is historical evidence that supports this practice being done on purpose to allow a pan to be placed as far to the rear as possible.

 

[oldwood]

When drilling the new , soon to be tapped hole , be aware that when the drill touches the breech plug , it will deflect toward the muzzle making the new hole oval shaped instead of round. Soon as the drill bit contacts the plug , stop. Use a bottoming tap to finish the threading and make sure the touch hole will fall close to the face of the plug. If the touch hole falls behind the face of the plug a small amount , the plug can be removed and a notch can be filed in the face of the plug to accommodate fast ignition. .............oldwood

 

[pooch156]

If you drill the touch hole and it touches the breech plug, all is not lost. Remove the breech plug and file a V shaped notch in the plug where it meets the touch hole, and forward toward where the powder charge will sit. This will allow powder to settle in this notch and will allow a slightly rearward facing touch hole to still ignite the charge. There is historical evidence that supports this practice being done on purpose to allow a pan to be placed as far to the rear as possible.

l Have done exactly this twice. Actually learned of this in "The Art Of Building The Pennsylvania Long Rifle".

 

[flntlokr]

My last one I had to make I used a allen socket set screw. Just ground it off some on top and bottom - then drilled a 1/16" hole in the middle. Having an allen recess in the darn thing makes removing to clean a snap. An factory liner with the allen socket is available from OX-YOKE if you stick with common thread type. Go with the smallest one you can find so will have the option to replace with a bigger one later on in the service life of the gun if needed. Install with teflon taper or anti seize. You will hear a scream here that says to NEVER remove a liner and another faction that says YES to clean - , but I do every few range trips to do a very complete cleaning job. And someday you may decide the hole is getting worn again and want to replace it - so that makes it even easier to service.

Exactly how I have done it for years! I can remove the liner easily with the alien's Allen wrench to clean. I screw in a short pipe with a hose attached, and pump cleaning soln. from a pop bottle. If I (heaven forbid) dryball, it is a simple matter to remove the liner in order to pry the ball off the breech face so more 4F gets in to blow the ball out, or , I also have a modified tire valve I can screw in to push the ball out using a tire pump or compressor. I cone the hole through the set screw from the inside end with a countersink, only leaving a very narrow shoulder.

 

[M. De Land]

Another though I had is that the liner itself does not need to be center drilled . The flash hole can be off center in any direction probably up to 25-30 thousands for plug face clearance and pan centering. As long as it does not intersect or crowd the liner threads in any direction all should be fine. I make my own liners from A-2 tool steel so can drill them off center if needed.

 

[M. De Land]

I don't like to change the flat plane of the breech plug as it is much easier to clean if left with no machine cuts or concaving of the face.

 

[M. De Land]

Does it make any difference where the flash hole intersects the powder column as far as accuracy is concerned ? Unless a patent breech is used it is always going to be to the side and bottom of the powder column.