Mossberg blues

Sometimes a deal thats too good to be true…is.

Case in point, the Mossberg 590A1 I picked up. Took it to the range today. Loaded it up, brought it up to my shoulder, pumped the action and…..a shell popped out of the mag tube, missed the carrier, and landed at my feet. Hmmm.

Apparently, every time I worked the action, the shell lifeter would go down but no shell would be released into it by the magazine. You don’t have to be a genius to figure it’s something with the shell stop tab or shell interrupter.

First things is first…hit YouTube and get a disassembly video. Pulled the gun apart, cleaned everything, light oil, and back together.

Same problem.

Now here’s where it gets interesting. One of the cool things about having redundant backups is that rather than guess what part was giving me trouble, I could simply swap parts from a gun that I knew was functioning perfectly, put them in the trouble gun, and see if that made a difference. I pulled a Mossberg 500 outta storage, disassembled it, pulled out the stop and interrupter, exchanged them, and….joy. But because I had a similar model to swap parts from, I was able to swap parts to find what was the problem part. The alternative was to guess, replace several parts, or hand the thing over to a gunsmith.

A quick trip to Mossberg’s website got me several replacement parts for $30. That puts my basis on the 590A1 to about $165. Still ahead of the game. And, as a plus, I learned how to completely take the bloody thing apart. And I picked up some spare parts.

I’ll take the 590A1 to the range again later this week to confirm function, and when the replacement parts get here I’ll put them in the ‘donor’ 500, function test it, and put it away.

Moral of the story? A handful of 12 ga. dummy snap caps would have tuned me into the situation ALOT earlier.

15 thoughts on “Mossberg blues

  1. All of which constitutes a reminder to “buy (multiple sets of) replacement parts now while they’re readily available and keep them on hand” for guns, chainsaws, axe handles, etc. Given the ubiquity of things like, say, 870s, some RemChester bolt/lever rifles, etc., it probably wouldn’t hurt to have a set or two of parts for them even if one doesn’t currently own an 870.

  2. I’m curious what the difference is between the good and bad parts. When you have them in hand, could you describe the issue? Something to be aware of with my own Mossbergs.

    • Tried that. I compared the two as closely as possible and saw absolutely no differences. I thought perhaps one was bent or ‘sprung’ a different way than the other, but they seemed identical. No idea what the differences were, but the results told me what I needed to know.

      • RE: 12 gauge snap caps….when you do, please let us know how differently they function, if there’s any difference, from regular loaded ammo, and the brand of snap caps. I’ve noticed feed/eject issues with (empty) dummy rounds made from fired hulls and loaded ammo, due to the weight difference/weight distribution. I’m reluctant to make any with weight because they’ll look and feel the same – an empty hull is easy to discern from loaded ammo.

        • There are two functions that you are looking at to simulate or handle.
          One is cycling performance. This requires fake ammo that feels and weighs about the same as real shells, otherwise your tests are not valid.
          The second function is to cushion the impact of the firing pin, which is what happens when it hits a real primer.

          An aluminum version may be fine for firing pin impacts, but may not be of much use for function testing.
          I have dummy rounds in 12ga, and the hull is white, which I’ve never seen in real ammo. Now, if I could just lay my hands on them…

          • The ones you’re thinking of are the Winchester produced dummy rounds. They are usually a clear/white plastic with a dark/black base and rim. We used them often in hunter safety class.
            The Z-Zoom snap caps are weighted and have the cushioned primer area.

  3. I’ve read about this being the shell catches/stop are sticking or need bending more.
    Remove trigger group, clean both catches and the grooves they are in, re-install.
    Or just send it to moss

  4. My neighbor bought a shotgun from someone at work, carried it around his homestead and on hikes for almost 2 years. I was up.oneday to shoot and he decided to try some of my heavier loads in his personal defense shotgun. Click, load another click, repeat several times. I asked him if he ever test fired it when he got it, nope. The poor guy had been carrying around a club for 2 dang years. It ended up being a broken firing pin. He’ll never make that mistake again.

    • Yeah, I used to know someone like that. He’d buy a gun, stick it in the safe and it would sit there for years if he ever even got around to shooting it. Id tell him that he had no idea if it worked or not.
      Every gun I buy gets some live ammo testing before I add it to the stash.

      • Even NIB is no guarantee of a functioning gun. Colt was infamous for this in the late 80’s. They have always claimed to test fire before shipping. Hah! A friend bought a 1911 that they hadn’t finished machining. Not even close to being functional, according to him. Not sure how he missed the problem, as he mostly bought 1911’s. Come to think of it, that might have been his last Colt. Not his last 1911, though.

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