What to use for getting out stuck breechplug

[roverboy]

A friend I work with brought me a barrel from a inline muzzleloader, that has a badly stuck breech plug. I've been soaking the plug it in Kroil for about 3 days with no luck. I tried it today and it won't budge. I've thought about using brake fluid. Any ideas?

[plainsman456]

Might try to warm up the barrel with a propane torch.
Not red hot just warm then try to get it to move.
It worked on the import 50 cal that my brother gave me.

[Ballistics in Scotland]

Yes, heat, up to the level that you can stand only the most momentary contact with your fingers, is likely to be the answer. But apply strong heat quite quickly, in the hope of expanding the barrel before the plug. Besides that, it should loosen anything some member of the intellectual classes may have used to seal the threads.

[kysunfish]

Mix acetone and ATF 1 to 1 and soak it. If you heat it (try to heat the plug) more than the barrel. I have had to make tools to remove them and nearly always end up buying a new one once the old one is out. Sunfish

[William Yanda]

Physics is your friend, heat the barrel and chill the plug. Expand the barrel, shrink the plug. That will break the lock on the threads allowing penetrating solution to work itself in and assist you in removing the plug. That's the theory anyway.
Regards
Bill

[Skirmisher]

Double check to make sure there is not a charge in it before applying heat.

[akajun]

Double check to make sure there is not a charge in it before applying heat.

Good call,
It sounds like your on the right track, kroil for days, applying mild heat, trying every few days. The only other things I would suggest is plugging the primer hole and filling the barrel full of evaporust and letting that work for a few days. I will say that do not fill it half way as the line where evaporust and air meet sometimes pits, so stand the barrel straight up and fill to the crown.
Other options are to use electrolytic derusting/ outers foul out type system or an ultrasonic cleaner.
If none of that works, a machine shop trip is called for.
This is why i keep a tube of anti seize in my MZ box.

[country gent]

Another trick is to set it up where it is exposed to very fine vibration while up right and with kroil or penetrating oil in it. let vibrate for several hours. The vibrations will loosen the torque and help to work penetrating oil into threads. One other big help is getting it in a solid barrel vise with correct inserts, where it is helpd solid and firm. This saves alot of the give and spring that lets things slip causing damage. A solid barrel vise makes it easier to apply pressure on the plug wrench evenly and solidly. Heat may be needed also. Vibration ussually does the trick but may take some time.

[John Taylor]

I use heat when thing don't move. There's also a big hammer next to the barrel vice that gets used quite often. Used it today to take a barrel off a 700 Remington.

[Ballistics in Scotland]

Yes, if your wrench is both heavy and securely enough fitting to avoid scarring by slippage, hitting it with a heavy hammer can have far more unloosening effect than just heaving on it.

[PTCSmith]

You removed the drum first, right?

[Screwbolts]

The 11th word in the OP is " inline " shouldn't be much of a drum to remove.

[altheating]

They make em so easy to take apart and clean nowadays, yet some are still to lazy to clean their MZ's. A tight fitting impact wrench may be needed.

[John Taylor]

Remembered that a few weeks back an inline came in with a rusted breach plug. Used penetrating oil and heat to get it out.

[Lee]

Heat the PLUG. Back when cars had drum brakes(!) I had to bleed the right rear, farthest from the brake reservoir. Naturally the plug was frozen rusted in place. I put as much force on it as I dared, but it would not budge. Kroil, ATF, etc, nothing... Called a friend for help, an ASCE mechanic. He said heat the plug as hot as you can, then remove it. Expansion/contraction theories be darned, but I figured he must know something I didn't. Heated the plug, and removed it with very little effort. That was 40+ years ago, and one trick I've never forgotten..... Lee

[country gent]

It is the expansion from the heat that breaks the "bond" of the corrosion. the expansion causes a small amount of mevement that breaks the corrosions bond. Fine vibrations do this also, as does light tapping on the plug. Theres alot of things to try with a stuck part. It may be the first it may be a combination of.

[curator]

Kroil soak, heat, large, heavy rubber mallet on a cheater bar. Make sure it is not loaded (obviously) this has worked for me even with AWBTS muskets. Make sure your breech plug wrench is the correct one. Sometimes a heat-cool, heat-cool, heat, sequence works miracles where brute force won't. Kroil or ATf/acetone is your friend.

[btreanor]

I would suggest heating the plug to break the corrosion bond (as mentioned above) followed by a lengthy (7 or more days) soak with Kroil. In any event, I have found that patience pays off with these sort of projects.

[mazo kid]

All good ideas, I like the Kroil soak and a small impact hammer or drill-driver.

[Edward]

Spray can of Blaster ,let it soak overnite and warm with a torch /tap while wrenching.It works on manifolds /engine blocks .