How do you remove the magazine tube from a Mossberg 500A 12GA shotgun?

Question

1 year old gun, it has an 8 shot tube and 20" barrel from the factory I want to have barrel options and for the 50 cal inline muzzleloader barrel I am attaching I need to replace the 8 shot tube with a 6 shot tube I have bought. Only the 8 shot tube won't come off, I don't want to wreck the the 8 shot tube it is only aluminum, it is threaded. I am looking for gunsmith advice or a chemical that will loosen the bond. Rob

Problem Solved! I put the receiver in my vise with cardboard to protect it not too tight, then using my pencil tip propane torch I heated the receiver not too much just a little where it was needed, I twisted the mag tube using a rubber boa wrench and tapped the receiver with the plastic end of a screwdriver. Thanks everyone!!! Rob

Answer 1

I have owned a Mossberg 500, but have never removed the magazine tube. I have, however, removed the magazine tubes from several other Winchester and Remington shotguns. The tubes are usually threaded into the receiver, but since the aluminum that the tube is constructed from is so thin, using standard tools isn't a good idea. If you have a strap wrench, try that. If necessary, warm the receiver a little where the magazine tube screws into it, which will expand the metal enough that the magazine tube will unscrew easier. You can use a propane torch, or just a candle, but don't heat it too much. Also do not heat the aluminum tube or it will expand and be even more difficult to remove. If none of that works, apply pressure trying to unscrew the tube with the strap wrench, and have someone else tap the end of the magazine tube with a plastic hammer while you are maintaining pressure with the wrench. Often the vibrations from the tapping will help break the bond between these two parts and allow you to disassemble them further.

If you do get them apart, post up what you did.

Answer 2

It's threaded as you noticed. It's simply tight from the factory.

Make sure your weapon is unloaded, first off.

Slide the bolt half way back so the ejection port is halfway open, and then unscrew the barrel retaining screw at the front end of the magazine. Remove the barrel.

Use a piece of stout leather or thick cardboard to protect your finish....and grip the end 3/4" of the magazine tube with some good pliers or visegrips. The end 3/4" FARTHEST FROM THE RECEIVER is the ONLY solid part on that tube! Grip it nowhere else!

Brace your left hand on the receiver right where the tube and barrel go in and give your pliers a good twist.

When you reattach the new mag tube, screw it in hand tight only! Don't strip the threads!

Answer 3

I am a gunsmith and I would personally recommend taking the gun to a gunsmith to change it out. It wont cost you much and you wont have to worry about damaging the old tube. if you want to do it yourself I suggest putting the reciever in a vice (don't colapse it, use the front of the reciever). Then you need a pair of nylon grip pliars or similar pliars and wrench it off. You may need to apply a good penetrating oil (WD 40 is not oil, use kroil oil) or even heat depending on condition.