Well, this has just cropped up recently. Got the gun in September, ran maybe 200-300 rounds through it at the range and took it hunting a few times for geese. Never had any problems then.

Last two range trips, a problem has cropped up. When shooting, the round in the magazine is ejecting under recoil. Sometimes all the way out, other times halfway out. Either way, I can't pump the action back or I do and get an empty chamber instead of my follow up shot. Pretty annoying, especially looking for live rounds on the range.

I took it apart the first time this happened and didn't see anything wrong, cleaned it good to make sure, but it came up again today within 30 rounds.

Any idea what's going on? Can I fix this myself or should I call Mossberg?

On the other hand, I never clean the action on my Mossberg 590A1 and it has performed flawlessly for thousands of rounds.

Turn the gun upside down and work the action. See that shell latch (on the ejection port side side) that pops out and holds the shell in the mag tube as you close the action? Is it failing to hold the shell in the tube? Often time this part will need a little bending (or replacing) to get enough tension on it to do its thing.

If that part is working OK then check the shell cutoff latch on the other side. Is the curved end moving in to postion enough to block the shell from moving onto the carrier (until the action is open)?

I don't have it in front of me right now, but when I last checked I didn't see anything wrong. Specifically this is happening under recoil. As in, sometimes the shell will pop out even if the action has not been cycled. I'm not sure if it needs to be  bent a bit, but then I wonder why it didn't pop up in the first couple hundred rounds? thanks for the advice though

If the problem persist just call Mossberg and work with them.

They will take care of you FOC !

I have the exact same problem... i thought maybe it was just me and my brother holding the gun at an angle while we cycled it... it was kinda confusing... whats up with that? i too have put 300-400 shells through it and it's like one every 20 or so it happens, especially on high angle shots..

bump

I had this problem on a mossy .410 my gramps gave me,
Here is what I did and it worked...
THe problem is comeing from the little hook that keeps the shells in the magazine until they are called for by pumping.
the hook on the right side(holding the gun upside down, looking in at the magazine.) It seems that the little hook on the end was not "out" enough(too close to the side not out far enough to keep the shell in the magazine.

anywhoo,
on a mossberg they are not staked in so its easy to take it out and give ity a little tweak so the hook in more hooked.
You can do it with the gun assyembled but run the risk of marring the side, if you pad the reciever, you can insert a flat tip screwdriver behinf the hook and give it a tweak.
well thats how us hillbillys do it.
ehunter