Picked up a project gun yesterday. Mossberg Maverick 88 that spent some time flooded with saltwater. Action cycles, trigger drops the hammer, so the main parts seem like they just need to be cleaned up. The problem is, the magazine tube is completely rusted up. the follower is rusted in place, the end cap screw was rusted in place. I was able to cut the magazine tube off with no damage to the barrel, but there is about a 3" section left stuck to the action. Its completely seized and rusted up. How would you all recommend getting it out. Penetrating oil, a bench vice and a pipe wrench? Or heat and then freeze? What say the old farts who've been around the block a time or 2?

For frozen motors I’ve used marvel mystery oil with good results. Having a hard time picturing exactly what you are working with but if you can get some sort of penetrating oil that’s my first step.

you can see my feeble attempts to bust it loose with WD40 and channel locks

Go get some marvel mystery oil and soak it.

Yep, Marvel Mystery Oil or PB Blaster, let it soak overnight and then hit it with the pipe wrench.

Just buy another one

yup. i could, but im only into this one for $60. i can replace the mag tube parts for about $45. Plus, i like projects.

I would do as recommended above and also use a wooden dowel on the inside of that tube or the fiberglass handle from that hammer to support the inside of the tube. If you crush the tube your done. And crushing it with a pipe wrench is an easy task. I over think thing though. Good luck!

And or soak it for a few days first.

thanks for the help everybody

What the suggested or Corrosion-x applied on at all openings you can get it to and keep soaking it that way. I have freed up several things that way on old farm equipment

forget the penetrating oil and get yourself a heat gun and and heat up the part. It has some serious lock tight on it from the factory. You dont need to get it glowing red , will actually screw it up if so. Just enough to break the lock tight and thats is. Place the receiver side in a vise, do not over tighten . Place some vice grips on the magazine tube to turn. Thank me later. aluminum and steel wont rust together.

ahh. thats a good point that hadnt even occured to me. i have a butane torch for lighting charcoal (you can see it in the picture) that should do it.

that didnt work. gunna have to get some penetrating oil.

Soak it in a mixture of automatic transmission fluid and acetone.

Have you tried cussing at it yet?

Yep. Kick it and cuss it.

Any chance it’s left handed threads?

A vice, two 2x4s to protect the action, and a dowel to fill the tube as stated above. A broom handle works if you don’t have anything similar.

If the action is aluminum you may not have any threads left in there already. It doesn’t rust but it does oxidize and it’s ugly.

Try some Kroil. Seems to be the best penetrating oil I have used.

X2

X3 on Kroil.

Bucket of kerosene with ATF mixed in. Drop it in the bucket for a few days.

Is that like blowing on old carburetors to make them work better?

If you had not cut the tube you could have ran a bolt with a jam nut in the threaded end. Snubbed it tight and backed it out with an impact wrench.
Now you need to measure the I.D. Insert a snug fitting piece of pipe or dowel. Drill a hole through it and run a steel rod through the hole so you can get some leverage. With the receiver in a padded vise, unscrew it.
Kroil is the best penetrating oil I have used. Soak it overnight. The threads may be full of salt though.
One other trick to try is heating the receiver with a cigarette lighter and rubbing a wax candle all the way around where the threads enter the receiver. The receiver will expand and the heat will pull the melted wax into the threads. That is an old mechanics trick to free stuck lug nuts without breaking the stud.
Disclaimer: I’m not sure what heat will do to the finish of your mossberg.
Edit to add: soaking fishing reels in white gasoline (lantern fuel) is commonly used to clean out reels that are full of salt deposits.