Stuck Breech Plug

[hawkenman]

I was given a Knight 50 cal. Disc rifle that was shot a couple of times, not cleaned afterward and placed in a closet for about 5 years. I finally got the bolt out but the breech plug is rusted in solid. I have tried soaking it for days in liquid wrench but it will not budge, the gun is not loaded. I have removed barrels and breech plugs before but this one has me stumped.

[Forestclimber]

See if you can get the nipple out.  Flush the barrel out in soapy water, then clean water, then shoot it some.
That might loosen it a little.  Also,  what if you put the barrel in a vise, heat it up around the breechplug, then try to remove the plug?  Don't heat it very hot, you don't want to ruin the temper in the barrel.   These are just ideas I have.  They may or may not work.

[DEACONLLB]

I did not want to say heat the nipple but as someone already has, a trick that I learned from a muffler shop owner was to heat the nut and then spray cold water on it for some reason it would cool and break the rusted nut free. Be sure to wear safty glases and good gloves and stand back. I would try the shooting first ,you might try soaking the nipple for a day or two with some crc that seems to work better than wd-40
I would also say make real sure the gun is not still loaded before you try the heating or any thing. One other thing if it does break loose you may have to screw it in an out a little at a time or it may hang up on you.
Deaconllb

PS if you do try the heat you may need to let the nipple cool as it will have expanded, also check with a good gun smith he may be able to give you a pointer or two.

[DennyRoark]

Try PB B'laster penetrant.  First, plug nipple and spray in muzzle and let set 24 hrs.  Tapping it helps.  If that doesn't get it, heat the barrel a little and spray some more in and let set overnight.  Screw the plug in and out like Deacon said.  If you get it moving, screw it out, spray some blaster and screw it in, repeat as needed.  I have been a millwright fo 30 years and that stuff is awesome.  Tap the barrel with a screwdriver handle or something else soft.  A hammer works better as it makes the metal resonate and helps it get into the threads better.  Only use the hammer after you've given up on the barrel, tho 

Denny

[hunt-m-up]

I heated my first CVA inline quite a few years ago because I wasn't aware at the time that anti-seize was a necessity, found out quickly though. I tried a variety of penetrating lubes to free it as well as very hot water in the barrel. Finally got out the propane torch and very lightly heated it with the breech plug wrench on and waiting to go. Water will cool it quicker, but may not be necessary as the barrel and plug will cool/contract at different rates anyway which should give you room to free it up if you start in right away after heating it. May need to smack the breech plug wrench rather than just turning it to pop it loose. I would try without the water first as to not affect the temper or warp something.

Thanks for the PB Blaster info. I've seen it and always wondered how it worked.

[SHOOTALL]

Plug the hole in the plug if it is open and put in some PB or Kroil and let soak a day or two . Then with a block of wood tap it some to make it vibrate a little . May need to repete several times

[hawkenman]

Thanks guys for the information, I found out a 7/16 socket would fit the breech plug and using a butane torch I heated it and it finally broke loose. I was disapointed when I saw the bore, it looked like an old cannon that had been in salt water for a hundred years. Well at least the gun was a freeby and I can use  it for parts. Thanks again.

[Doug B.]

Try PB B'laster penetrant. 
Denny

I was told by an old timer some time back that rust penetrants such as JB 80, PB Blaster, Liquid Wrench etc. should not be used on any sort of blued surface because he thought that bluing is a form of "rust". I have not researched this and was wondering if anybody has had any good/bad experiences with these types of lubes. Are there some that absolutely should NOT be used? 

[DennyRoark]

Good point about the bluing and Blaster, Doug.  I've never used it on a gun, but it literally disolves rust.

Denny

[SHOOTALL]

It did not affect the guns we used it on but that dosen't mean it won't others . try it in a place that won't be seen . WD-40 is used to stop the bluing process .