mossberg 500a mag tube removal

[Rob1035]

Hello all,
I'm trying to replace the broken/poorly welded/rebroken slide action assembly on my beater 500A. Scored a new forend with assembly on ebay, but I'm having a devil of a time figuring out how to get it on. It appears I need to remove the magazine tube, but I have no idea how, and the manual doesnt go further than field stripping. Any insight? I'm hoping not to have to take this to a 'smith

Thanks
rob

 

[mnrivrat]

Removal of the mag tube is not needed to replace the action slide assy on the 500A.

Compare closely the old assy with the new one - you may have gotten a Maverick assy, or something else , but it is not the correct replacement part if it will not slide straight over the existing mag tube.

To remove the tube by the way you should clamp the receiver into a padded vise and use a strap wrench on the tube next to the receiver - right hand threads so remove counter clockwise. Sometimes they are stubbern and require a little heat on the receiver where the tube screws in. (a little heat will expand the aluminum and help break the bond - don't overdue the heat !)

 

[EricTheBarbarian]

the magazine tube on the mossberg 500 threads into the receiver. It is probably going to be hard to turn but you need to just grab down hard and turn the magazine tube in a counter clockwise direction. after you get it out id add some oil to the threads so they come out easier next time.do that after you take the barrel off of course.

 

[Rob1035]

thanks for the help guys, i'll explain the situation. The tube that the forend is secured to broke from the piece that the action bars are attached to. Evidently, the previous owners fix was some welding, which broke again a few weeks ago while shooting clays. On the magazine tube, there are two rings that appear to be permanently attached that preven the action bars (and the thing they are pinned to) from being removed. I dont know if this is how it comes from the factory or not though.:banghead: The ebay parts appear to be identical, so I dont think thats it...

My 'beater' has turned into a project

edit- i've attached pics of the broken part and the new part for reference

 

[mnrivrat]

Ah ! One of those set ups where you do in fact have to remove the mag tube. They haven't made them that way for a good long time and I think you may find that the second ring you speak of on the mag tube is actualy a flat spring . Anyway, remove the tube as indicated and the forearm front nut has to be removed (the one that holds the wood on) the washer and stop ride inbetween the two ends of the forearm.

 

[Rob1035]

cool deal, i'll try it out.

I must say though, I really love the tired old girl, but this is making me contemplate buying a second mossy, so as to have a working shotgun when one is down. So it begins....

 

[Third_Rail]

I have a single action bar Mossberg 500a, and it doesn't have that problem - was that just with early double bar 500a models?

 

[mnrivrat]

I have a single action bar Mossberg 500a, and it doesn't have that problem - was that just with early double bar 500a models?

The model 500 Mossberg was a re-design of the Hi-Standard pump shotguns. These guns had an action slide spring . This is a flat spring that bears against a fixed collar on the magazine tube and the rear inside of the metal action bar tube .

I think it was more or less a feature to keep the forearm under a little tension thereby giving the impression of a solid no-rattle gun. It served little other functional purpose.

I don't know the exact history of when and why Mossberg incorperated this part of the Hi-Standards design into the 500 but it seems reasonable that it was with very early production models and was then dropped as a cost savings finding it to be not all that necessary.

So in order to assemble this system you have to have the magazine tube removed and also the front slide action bar forearm nut - the tube is then slid into the forearm with the rear portion of the tube sticking out the back and being retained by the spring and collar - then the front forearm nut is threaded on containing the magazine tube within the forearm .

The single action bar was standard for quite some time on the 500 and they may even have dropped the dual action bar at one time to go to the single action bar and then back again. The second bar lends some smoothness and stability during the pump action cycle over the single bar versions.

 

[Third_Rail]

Mine is pre-1968, and single bar. I didn't think they were made for that long before 1968!