Breech Plug Removal

[QuanLoi]

After many thousands of rounds, I have to replace a touch hole liner on a gun I built in the late '90's.  I intend to install a 1/4 x 32 White Lightning liner but because of the position of the current liner being so far back that it overlaps the plug face a bit, I may have to remove the breech plug.  Is there anything I should know about, any cautions, any tips on removing a breech plug I installed almost twenty years ago? 

Thanks for the info...

Decker

[smylee grouch]

What thread size is the old liner?

[QuanLoi]

I believe the old liner was 1/4 x 28.  It was of the old slotted type.  After a liberal dose of Kriol, I tried removing it using a screwdriver...ng  Then an easy out which tended to shred the liner... also ng.  The liner overlaps the plug face by about 1/16" or so.

[Jim Chambers]

First, you cannot install a 1/4 - 32 liner in a 1/4 - 28 hole unless you want the liner to blow out at some point.  You can install a 5/16 - 32 liner.  The drill for the 5/16 tap will just remove the 1/4 - 28 threads.  As long as your barrel has enough width on the flats for the larger liner you should be ok doing this.
Yes, you will definitely need to remove the breech plug to install the new liner.  I would first soak the plug for a day or two with a mixture of half transmission fluid and half acetone mixed together.  That is the best penetrant by far, far superior to any of the commercial products according to testing by Popular Mechanics.  Just plug the touch hole and pour some of the mixture down the barrel, and let it sit.  Once you're ready to remove the plug clamp the barrel is a sturdy bench vice with about one inch of the breech extending beyond the vice jaws.  Also, you need metal to metal contact, so use brass or copper (definitely not wood, rubber, or leather) to prevent damage to the barrel by the vice jaws.  A sharp blow on the end of a large wrench should break the plug loose.

[wet willy]

Removing the breech after 20 yrs might be a problem. Good soak for a week in Kroil, etc should be the start. Some leather pads, big crescent wrench, long cheater bar, big & secure vice w/padded jaws to hold barrel are needed. Some touch hole liners are made with different diameters, so if you drill one out, you could go to a larger size replacement.

Many touch holes were positioned into the breech plug. The 'smith just made a groove/notch/channel/hole into the face of the breech plug to allow the pan flash to get to the main charge.

Installing the liner can be tricky: too long and you'll snag patches, too short and fouling accumulates (or worse if too threads engage the breech and the liner blows out!)

One needs to adjust the length of the liner to be flush with the inside of the barrel. The cut-n-try method involves filing the liner, trying it, try again, so you sneak up on the final length. Another method is measure/calculate the breech wall thickness, trim the liner to length. Both methods involve holding the liner, which can be tricky. Fingers are not an option, but some have succes with parallel jaw pliers & grinding wheels, small lathes, and drill press vises.

[rich pierce]

Plug might come out easy.  Doesn't hurt to just give it a try.  I've checked the threads and condition of the plug on old rifles before and had them unscrew the same as when new.

[Eric Krewson]

Hopefully your liner isn't like the one in one of my rifles, threaded into the breech plug. I was going to pull the plug and file off the excess (the plug hasn't been out in 40 years, I didn't make the rifle) until I noticed the threads for the liner went into the plug. The liner is frozen solid and won't unscrew.

[L. Akers]

I was once asked to clear the breech on a 1862 Springfield which appeared to be loaded.  I set the breech in a soup can and filled the can with brake cleaner.  Poured some down the barrel also.  Left the barrel in the cleaner for a month, then started to work.  I couldn't get a ball puller to bite into anything so unbreeching was the alternative.  I made a "wrench" from a piece of 1-1/2 x 3/8 steel bar to fit the plug, cramped the barrel in a large vice and tried to unscrew the plug.  It didn't move so I tried to tighten it.  Still didn't move.  I kept trying to alternately loosen and tighten the plug.  After a couple of minutes I could see liquid squeezing out around the plug.  Another couple of minutes of working the plug back and forth and it gradually loosened and came out.  Someone had driven a wooden plug down the barrel to make it safe for kids to play with.  I relate this to illustrate a removal method which worked on a barrel that had been breeched for over 100 years.