breech plug not fitted properly

[RichG]

have a smooth bore with a breech plug that doesn't seal. I've taken it out shooting 5 or 6 times now. This last time I noticed water on the breech area of stock while cleaning. Took barrel out of stock and unscrewed breech plug. Didn't need a wrench to remove plug. Plug was covered with powder fouling and anti seize. 3/4-16 threads, so if I refit plug I'll have to re-drill tang screw whole and lock bolt screw hole. Also gap on tang. Other than fitting a new breech plug, drilling and inletting new tang etc. does any one have any Ides? Could lock-tite be used to seal threads and keep the fouling out of threads?

[smylee grouch]

Is the plug too short of threads lose?

[RichG]

the plug appears to be short of bottoming out and loose until it is lined up with top flat.

[smylee grouch]

I'm thinking a short plug will create a fouling trap with all its potential bad effects.

[rich pierce]

Obviously a new plug with a longer threaded length is going to be the best engineered solution but as you note necessitates fitting the inlet and drilling tang bolt.

Removing 0.055” from the breech end of the barrel will re-align the top of the tang with the current top flat. Holes or slots in underlugs would have to be extended by that amount. And the face of the plug would be tried gut fit and relieved as needed to get both the extra full turn of the plug and a good seal.

Extending the length of the threaded portion of the breechplug is theoretically possible by welding on but you’d have to be mighty good with a lathe to make the threads extend through the material added to the face of the breechplug. Then test and remove some of the material added at the face as necessary to align tang with top flat and get a seal.

[RichG]

Obviously a new plug with a longer threaded length is going to be the best engineered solution but as you note necessitates fitting the inlet and drilling tang bolt.

Removing 0.055” from the breech end of the barrel will re-align the top of the tang with the current top flat. Holes or slots in underlugs would have to be extended by that amount. And the face of the plug would be tried gut fit and relieved as needed to get both the extra full turn of the plug and a good seal.

Extending the length of the threaded portion of the breechplug is theoretically possible by welding on but you’d have to be mighty good with a lathe to make the threads extend through the material added to the face of the breechplug. Then test and remove some of the material added at the face as necessary to align tang with top flat and get a seal.

I didn't think of removing material from barrel. I'll have to check vent hole location and underlugs. might be a good alternative. thanks for the Idea.

[Scota4570]

Measure how deep to the shoulder before you commit to trimming the breech end of the barrel.  IF it works out, you may end up having to notch the face of the plug for the flash hole. 

Depending on how badly the original job was botched I might consider sealing it up with RTV.  Only for my own gun though. 

[bob in the woods]

I had a gun in my shop years ago, which required deb reaching in order to remove stuck ball  . I was surprised to see that there was a spacer/plate silver soldered to the plug face to effect a seal .  Not my fix, but it seemed to work .

[WKevinD]

I've seen some new (recent) barrels from an older barrel mfg with a new owner that would leak water at the breech.
Sad thing to see, used to be the only barrel mfg. I would use.

Kevin

[mountainman70]

How about getting a new 3/416 bolt fit it against breech face , cut and make new tang or cut old tang off of plug and weld it on new plug then fit into stock?
Just a thought.
Best regards, Dave

[bluenoser]

I believe the fix bob in the woods came across is the best solution, followed by TIG welding and dressing down the breech face, with the former being much easier than the latter.  The threads should not be a problem.  A little work with a small 3-corner file should be all that is needed.

[Steeltrap]

I had a gun in my shop years ago, which required deb reaching in order to remove stuck ball  . I was surprised to see that there was a spacer/plate silver soldered to the plug face to effect a seal .  Not my fix, but it seemed to work .

I'd say this was a good\great suggestion. Breech plugs are "fairly soft" metals so adding a small extension like this would not cause any other alignment issues.

And I agree that a 3 corner file to finish out the threads should work fine.

[Rawhide Rick]

Could a wrap around the base of the barrel threads, with thin aluminum wire, work?  Sort of a home made crush washer.

[davec2]

Had a similar situation on a rifle a friend brought to me to work on.  As what I thought would be a temporary fix, I machined a disk out of copper that would fit in the breech and was a little thicker than the gap.  Tightened the plug into place and it made an excellent "crush" seal.  Checked it again after about 18 months and a lot of shooting and cleaning and the disk was tarnished on the powder side face but in otherwise perfect condition.  I had thought it would need to be replaced but it was in such good shape I put it right back and tightened the plug.

[RichG]

I measured the distance from the breech to the touch hole liner and I have .050-.060, so cutting off the back of barrel is out. I like the Idea of soldering on a crush washer. I can solder, don't have any way to weld. It's a Getz barrel and there is a nice shoulder from the end of the drill. The plug also has a nicely beveled lead on the threads. Plug just appears to be about .030 short   

[Steeltrap]

Silver solder with MAP gas should work.

[bluenoser]

No need to use silver solder.  The joint is under compression and soft solder will be plenty strong enough.  Tin both parts.

[Dphariss]

have a smooth bore with a breech plug that doesn't seal. I've taken it out shooting 5 or 6 times now. This last time I noticed water on the breech area of stock while cleaning. Took barrel out of stock and unscrewed breech plug. Didn't need a wrench to remove plug. Plug was covered with powder fouling and anti seize. 3/4-16 threads, so if I refit plug I'll have to re-drill tang screw whole and lock bolt screw hole. Also gap on tang. Other than fitting a new breech plug, drilling and inletting new tang etc. does any one have any Ides? Could lock-tite be used to seal threads and keep the fouling out of threads?

I don’t know of any of the “custom” barrel makers that I would trust to fit plugs properly. Kiblers have been good, the ones I have pulled (2), but some others are down right scary. I don’t want a barrel with a fitted breech plug. Rather do it myself.