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Mossberg 930 Autoloader Troubleshooting

Only thing I would suggest is a full teardown of the bolt assembly. There may be some preservative gunked up in there around the spring preventing the firing pin from making full contact...
 
Also, make sure the barrel and piston assembly are fully seated to the rear and the mag tube cap is tightened down all the way. If the barrel is shifting forward at all there is a possibility that the shell is positioned too far forward...
 
Just one more thing. I am grateful for you guys, and girls here for your posts, Good, Bad, or Indifferent. I think this helps people as to what to expect, or maybe look out for from any firearm they plan to buy or maybe already have. This forum give me the info I needed, to make a battle plan of attack, for when I received my shotgun. I knew the first thing to do was a complete scrub down, not just a cleaning but a SCUB DOWN. I always new you should clean any firearm you received, but I did not know how much shipping grease Mossberg used, until that is, I read it here.
Thank You All Very Much.
Thee American Icon
Buff Studly


After applying virtually ALL of the recommendations here, my last range session with the 930 went well. True, it is only one session, and I won't be fully comfortable with this as a primary HD gun until I run a substantial amout of ammo without issue.

HOWEVER, it is a welcome bit of good news and a light at the end of what has been a very dark tunnel. I too appreciate all the tips and advice I have found on this forum. I will continue to update as my testing progresses. At some point later on, I will also try to detail the things that I found here and utilized in one single post. Maybe it will help "pay it forward" and help someone else in the future.
 
I decided to sell my 930 spx, I did the or3gun kit in it and it still had hiccups on occasion. I lost confidence in it. If I can not expect it to go bang anytime I pull the bang trigger, it is just not something I want . It just was not 100% reliable. I thought I had it all worked out and could live with it, but I just can not live with it and second guessing its reliability.
On the hunt for a 590, or 590 A1, good old reliable pump that will go bang every time.
Cheers.
 
I decided to sell my 930 spx, I did the or3gun kit in it and it still had hiccups on occasion. I lost confidence in it. If I can not expect it to go bang anytime I pull the bang trigger, it is just not something I want . It just was not 100% reliable. I thought I had it all worked out and could live with it, but I just can not live with it and second guessing its reliability.
On the hunt for a 590, or 590 A1, good old reliable pump that will go bang every time.
Cheers.
Deog I understand. These firearms need to be reliable, after all your life and your family's life depend on it. Just one hiccup as you say at the wrong time when it counts will change your whole life for the worse.
 
I have been having mixed results with my JM Pro. A lot of FTF and failure to extract. Mossberg sent me a new barrel and today found out it is no better with Winchester Super X shells (1255 FPS, 1 1/8 oz.) Shells are being left in the chamber and extractor is tearing the case lip. 2016-02-06 15.33.23.jpg Any ideas, Mossberg or Winchester problem?
 
I have been having mixed results with my JM Pro. A lot of FTF and failure to extract. Mossberg sent me a new barrel and today found out it is no better with Winchester Super X shells (1255 FPS, 1 1/8 oz.) Shells are being left in the chamber and extractor is tearing the case lip. View attachment 10843 Any ideas, Mossberg or Winchester problem?

I had the same problem with a few bulk Winchester shells I tried. No problems with bulk Federal shells.
As a matter of fact, the Winchesters exhibited the same bulging case heads too.
 
I have been having mixed results with my JM Pro. A lot of FTF and failure to extract. Mossberg sent me a new barrel and today found out it is no better with Winchester Super X shells (1255 FPS, 1 1/8 oz.) Shells are being left in the chamber and extractor is tearing the case lip. View attachment 10843 Any ideas, Mossberg or Winchester problem?

Most folks around here have the same issue with that ammo...
 
Have a 590 that I am very happy with. Bought it new in 1991 and Mossberg covered it under warranty over 20 years later. I am a happy owner.
 
Re: Bit by the scratched magazine tube problem

oh for goodness sake ! I read alot here about the "burr scratching" issue and feel it's almost a waste of time as well as a BIG hassle to ship the gun back to Mossberg .( with the possibility it will just happen AGAIN ) I like Poopyants and his fix ; thats what I will do ........and I will try to get Mossberg to send me a new tube
 
Let us know how that works Lefty Mine had a stripped recoil pad screw, so I shortened that stock and the tube along with it.
 
ok guys..first off..thanks for all the input, shared experiences, etc. I just came back in from my backyard range time..and for the first time in over a year owning my 930, I am now finally able to reliably cycle plain ol Estate and Remmington #8 shot. Prior to this, it would run Rio or Spartan cheap buck about 85%, and really only eat full brass Remmington sluggers or Federal buckshot.. and of course prior to that, brand new out of the box, it had the dreaded stuck lifter issue that sent it back to mossberg for replacement. i had become so dissolusioned with the gun that I had hoped to get it running somewhat reliable and then sell the thing cheap with full warning to a buyer not to trust the gun...but even at that, I'd feel guilty selling it..as mossberg should well have been also.
anyway..about 400rds of buck/slug through it and this last time cleaning, i took extra care to really polish the piston and walls and put it back together extra wet..the piston felt notably smoother.
I then hit the range and found that it now cycles even light #8 shot..in fairness to the gun I did make sure i was running at least a 3 1/14 dram but still was only pushing 2 3/4 shells of #8..in both Estate and Remmington cheapo.
mind you, I own multiple mossberg pumps so I'm not trying to be anti-mossberg...what I am saying is that it looks like it comes down to some care in fit n finish that you may not be fortunate enough to have gotten when it was built...but if you put a bit of time into the gun...it can be made to run reliably. The market on these guns has not increased..in fact it's fallen a bit since I got mine..so no sense in trying to sell the thing right now..
I would never consider this as my home defense gun.. Ihave a proven 500 Cruiser for that...but i do expect to continue to enjoy just backyard range fun with the 590 now..will continue strict cleaning/maintenace and who knows, one day it may prove itself to me and wind up as a go-to when the zombies are overrunnin the front porch.
 
I bought my 930spx about 3 months ago as a used gun and immediately had problems. I sent it back to Mossberg and they replaced the gas system and the shell stop assembly. The day I got it back, I took it to the range to try it out. After 3 rounds, the rear shell stop pin (the pin under the bolt release) fell out! I called the service dept. and they sent me a new pin with 3 new clips, but in the meantime, I pushed the pin back in and sealed the top (bottom?) with a dab of Goop. It's a strong adhesive and dries to a rubbery consistency. It seams to do the trick. I'm still having a bit of trouble with failure to eject my Winchester Super-target (1180 velocity) rounds. It happens a couple of times per box. I understand that this shotgun doesn't particularly like Winchester ammo. It's a shame a tactical shotgun has to be so finicky. What is this or3gun kit and what problems does it address?
 
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