Another Bore image and question

[Molly]

This is on an "old" rifle dating from around 1800 to 1810.  It is a flintlock.  If you were to insert a small wire through the flash hole it will appear between the camera and the object which appears to be at the breech.  So what exactly is that line that looks like a screw.  I think I have seen something similar on another rifle but not sure.  Using a cleaning jag you cannot "feel" this screw looking object.  Using a spiral patch puller you cannot feel it either so it seems to me that it is a mark or "scar" on the face of the breach but ??

[Bigmon]

Looks like a continuation of the vent hole.  Like when it was drilled it scared the face of the plug.  Ot maybe they removed the pluf and filed a slight groove in the face because the vent hole was back against the face??

[Karl Kunkel]

Molly,  Is the touch hole up against the face of the breech plug?  Might be from drilling the touch hole, could be intentional to open the path from touch hole to charge?

(Bigmon types faster than I do!)

[Molly]

This could be the answer.  Yes, the center of the hole is about 3/8th inch off the absolute back of the barrel.  Just quickly looking at other rifles in the stable it looks like that is about 1/2 the length of the others so I can see how the drill could have accidentally cut the face of the plug OR that it was done intentionally so the plug did not block the path to the charge.

You guys are very helpful.  I'm going to check out some others tomorrow.

THANKS

MAS

[Jacob_S_P]

Frequent and common. The hole needed to be as close to the face of the breechplugas possible in order to make sure the the flash made it to the powder and not into the side of the patched projectile
All of those I studied in my stable, seem to have had the breech plug installed and indexed, then drilled, then it appears the breech plug was removed and the slightest groove filed in to make a clear path for the spark to travel a direct path to the primary powder charge.
Brilliant and ridiculously simple.

[Eric Krewson]

I have a rifle from the 70s, when the touch hole was drilled for the liner, the builder hit the breech plug. It looks like he threaded the breech plug some for the liner.

 

[BFox]

Molly,
Here's a period (1760s) illustration from Diderot.

Bernie

[Dan Fruth]

Most barrels today use a 1/2" long breech plug, so the vent at 3/8" is into the plug. Your handy husband could remove the barrel, unscrew the plug, and file a vee like pic on BFox's post, and you'd be all set.

[WESTbury]

Molly,
Here's a period (1760s) illustration from Diderot.

Bernie

Molly,
Roughly the same condition in the breechplug of the Ferree rifle restored by JTR.
Kent
https://americanlongrifles.org/forum/index.php?topic=72513.msg729359#msg729359

[Molly]

Most interesting.  I can see that there may have been a need to do this but it also seems to me that in a perfect arrangement you would not want to have to do this. Seems like it could lead to an accumulation of fouling in that crevice and that could result in mis-fires.  But of course a long breach may make it necessary.

Dan:  This is on an original flint lock...we were just trying to figure out what it was.  I did peak down the bore of the Woodsrunner and noticed there is no such "thingy" down there.  You can actually see just a very short turn of the thread of the liner and it is essentially flush with the inside of the bore.  You made us a really great rifle.  THANKS

Molly