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Mossberg 930 Autoloader Troubleshooting

I wasn't done. Not sure what happened. Anyway, I am shooting a JM 930, 9 round. I have had it apart and cleaned it thoroughly and removed the mag shell stop and polished it and everything else I can think of. At our local 3 gun match, they often have us pre-load our shotguns, and leave the chamber empty (chamber flag in). So I get to the line, and with a full mag tube, drop the bolt. When I do this, it double feeds above the lifter, and drops at least one round out the bottom under the lifter. It does this every single time. My buddy used it last time, and when he did it, it just kept pumping shells out the bottom until it was empty. Pretty embarrassing! If I load the chamber first, then drop the bolt and load the magazine, it runs just fine. Incredible in fact. But every time I load the magazine only, then drop the bolt on an empty chamber, it drops a shell out the bottom. Sometimes it feeds one shell above the lifter into the chamber, and about half of the time it double feeds. I have gotten good at pushing one shell back into the mag tube, but this takes a LOT of time. I cant shoot a match like this. I know it is getting picky, but it has to work right. BTW, I cut my mag spring down-it was around 18" long when new, I have it cut to 11 1/2" beyond the end of the mag tube with the stock follower in place. I have just about ordered a new follower several times, but i want to get it to get it working right before I make any changes to it. Let me know if you have any ideas. Thanks for this great forum!
 
Welcome aboard.

Sorry to see you're having this issue. Is this a new shotgun? This double feed and crapping shells onto the ground is not uncommon. The usual suspect, especially in new guns, is insufficient recoil energy due to underpowered ammo or the bolt binding up in the receiver. The issue typically resolves itself after a short break-in period. I understand that yours is only dumping during the initial charge, but functions as normal under recoil. I had the EXACT same issue with my 18.5" 930 during the first 100-120 rounds. After that, the issue resolved itself with no modification to the weapon. I would suggest running a few boxes of high brass through it, starting with a loaded chamber, and give the action a chance to wear in a bit before modifying anything further...
 
Good to know. I have about 150 rounds through it, maybe a few more. But maybe it does just need some more ammo through it. I have been so consumed with trying to get it working that I haven't been taking the time to shoot it! I'll give it a try. Thanks Sniper.
 
Scott Smith said:
Good to know. I have about 150 rounds through it, maybe a few more. But maybe it does just need some more ammo through it. I have been so consumed with trying to get it working that I haven't been taking the time to shoot it! I'll give it a try. Thanks Sniper.
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No problem, keep us posted.

If the problem persists we can try to dig in further until we get you up and running 100%...
 
Thanks for your input too MikeT. What do you suppose the trigger group had to do with double feed problems? I am just curious how it cold affect it. You could be right, I am not contradicting you, just trying to figure this out. Do you think it has to do with the timing of the lifter?
I also wanted to mention that I emailed Joe Z at Mossberg (or is it Maverick) and he called me the same day. He left a message because I was unable to answer when he called. I called him back and now we are playing phone tag, but I thought it was real good service for him to respond so quickly. I did mention that I got his info from this forum. I will let the forum know what he has to sa once I speak to him.
 
Joe was the person who identified the DF issue as being the result of the trigger group. As to why, I never figured that one out as I did a pretty hard start and compare and could not measure / see any differences. However, after the TG replacement.... Zero issues. While speaking with Joe, I recommend you pick up a couple of spare Pusher Assemblies (The doo-hickey with the two steel bars that contact the bolt assembly).
 
Mine also only likes to be loaded one way I don't shoot 3 gun so not a problem for me can you ghost load one then when you step to the line just rack it back and go
 
Gunned down said:
Mine also only likes to be loaded one way I don't shoot 3 gun so not a problem for me can you ghost load one then when you step to the line just rack it back and go
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I can and have done so a couple of times just o try it. ghost load, but I do not for competition.
 
Scott Smith said:
I wasn't done. Not sure what happened. Anyway, I am shooting a JM 930, 9 round. I have had it apart and cleaned it thoroughly and removed the mag shell stop and polished it and everything else I can think of. At our local 3 gun match, they often have us pre-load our shotguns, and leave the chamber empty (chamber flag in). So I get to the line, and with a full mag tube, drop the bolt.
Click to expand...
I suggest looking at that magazine shell stop again. I suspect it's letting two shells out frequently You may have "polished" it too much, or not gotten everything put back the way it was, or still have a magazine spring issue, i.e. too much. The other thing I found on mine, push the bolt release briskly, mine doesn't like a soft push.
 
I always figured mag spring if you loaded first with action open spring pushes back to hard carrier dips then when you close the action half loads a shell and jams my ok as long as you out one in the chamber first them load the mag tube
 
Feelin a bit foolish now....finally went to the range Friday night after work. Loaded her up and went to pull the trigger and nothing happened. The trigger was fully depressed and wouldn't reset. So I took the trigger group out real quick and noticed that the trigger pivot pin had fallen out the last time I put it together. Got home and there it was on the floor of my reloading room. DOH! I will have to try again to see if it is working better yet. After I put it back together correctly I played around with it and it seems to be working better. Not perfect but better.. I still haven't been able to talk to Joe just because I am too busy all day at work to call him but I will soon.
 
It happens. Earlier this year I launched a P938 safely plunger/spring twice in the same evening. Fortunately the 2 are captive. The last time I heard the "tink", but couldn't find. I was thinking, that "was" kinda high pitched. Ah! The window, sure enough there it was on the sill. I now always turn it towards me, or do it in big clear plastic freezer bag. Good luck.
 
The forked lifter keeps biting my thumb every time I load a shell. I am not happy with that. Now I have to send it off to get worked on.
 
Does anyone notice their 930 has a loose trigger assembly? Mine is somewhat loose, and the pins are definitely seated all the way.
 
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