I hope you're not using that breech plug wrench that came with the rifle to try and get the stuck breech plug out. I did and broke mine. You will only end up scuffing the breech plug. Get a extention and your socket set. A 9/16th socket I believe or 7/16th is the one that fits the plug. An eight inch extention will go all the way in through the back of the breech.

Get a pan of boiling water on the stove, and in a bucket a bucket of ice cold water. Take the barrel somewhere like outside and set it up and pour boiling water down the muzzle of the barrel and through the breech plug. The idea is to break the fowling and at the same time heat the barrel up real good.

Once you're sure the barrel is real hot (wear gloves), dunk the barrel in the ice water. Let it sit there about two minutes. The idea is metal will expand and contract when subjected to extreme temperatures breaking the seized plug. Now get the wrench on it quickly and tap the handle of the socket to jerk the socket. This will usually pop it free.

If this does not work, then plug the 209 breech with something and put some liquid wrench or penetrating oil down the barrel and see if it will break it loose. When I did the same thing, the water trick worked, but I stuck my barrel in a vice after the water and hit it with an open end wrench (after taking the scope off... [:@] m).

Be sure and rinse the trigger out real well after pushing the fowling out through the breech plug. Some of that will get into the trigger assembly and it has to be washed out. Then spray the trigger down good with some WD-40 or something.