lose breech plug

[redheart]

I would want to know why proofing the barrel loosened the plug.

I'd love to know that too.
What kind of proof load did you use?

[curly]

My proof load was 60g


    curly

[J Henry]

  Contact the M.F.G. and send it back,Manufactures defect, could be the plug blows out when you fire the rifle,now if you figure your head in relation to where the plug will travel ,it could spoil your afternoon.

[Dan Fruth]

This is how I would think through this issue...1- Did I have the breech plug threaded All the way into the barrel when I tested the barrel.....Did the internal face of the plug bottom out the same time external face met the barrel........It does not sound like this was the condition when you tested the barrel.....The only way you can use this plug is to file material from the internal  face of the plug and the breech face of the barrel until you make a complete revolution , both faces are bottoming , and the correct flat is aligned.....SO- it would be WAY easier to get another plug that is long enough to...1-have both the internal and external surfaces meet, and the correct flat matches the tang.....Welding up the face of the plug won't fix the problem with the tang out of alignment with the top flat of the barrel....I hope this makes sense.....This is just my 2 cents

[Dan Fruth]

If you are sure the plug was seated properly before you test fired the barrel, and it is now 1/2 turn loose....I would say the threads must have deformed with the pressure of the explosion, and there is no way I would use it......What barrel is this anyway?......If it is a 5/8 or 3/4 thread, or any thread for that matter, there is a standard for the % of thread interference, and if the counter bore in the breech of the barrel was too large, I could see the plug blowing back when fired......Either way, you need to examine to see what happened.

[redheart]

My proof load was 60g


    curly

Thanks Curly,
Wow! That wouldn't even be classified as a proof load unless you loaded numerous balls in front of it.

[shortbarrel]

you can talk all day about the fixes, but I want to know why the barrel set back in the threads when proof fired. someone could get hurt trying some of these fixes.

[bgf]

I'm starting to think it was clocked with thread locker, epoxy, or such, and not installed correctly in the first place!  I'd be wary of plug and barrel at this point, not to mention whoever installed the breech plug.  I would talk to that person and find the facts.  If you're lucky, a new plug will fix it, after the barrel threads are checked.  Worst case, New barrel, if threads were deformed..

Did you remove the plug only after firing the proof shot?

[Flint62Smoothie]

I'm starting to think it was clocked with thread locker, epoxy, or such, and not installed correctly in the first place!

... that's exactly what I'm thinking too!

[Ky-Flinter]

Guys,

I don't believe the "proof firing" with only 60 grains of powder made the breech plug get loose.  In the 2nd reply in this thread, the owner of the barrel stated the following.....

The plug must have been louse from the beginning Dane. When I removed it, it had some kind of compound on it, like pipe dope. So whoever installed it at the factory knew it was louse to start with.

The lesson here is, when you acquire a barrel, check the breech plug fit before doing any other work on the barrel.  It's a little late now, but you could contact the barrel maker.  If they replace the barrel, properly breeched, you would still have to install the lugs in it.  Or just order a new breech plug and fit it .

-Ron

[J Henry]

  Why even take a chance,, contact the barrel maker, then send it back.Think about it,if /when any thing goes wrong ,you will/might never know it,What caliber is a breech plug??? Even if you cobble it and it works,you will always wonder, is this the time or is today the day it fails.

[curly]

Thanks for all your input guys. I contacted the manufacture. The barrel is on its way back. He is going to make things right, less shipping. For the amount of money I paid for this barrel, having it right isn't to much to ask.
                                        Curly

[Waksupi]

Sounds like the best thing to do. Breech plugs need to fit well, not necessarily gorilla tight. I used to shoot modern benchrest competition. Some of the guys might change barrels a couple times during a weekend match. Most could be removed by hand with no tools when the barrel was heated a bit. Certainly working with higher pressures that we do with black powder!