Problems with Mossberg 930 SPX

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EdLaver

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I have had it for three months now, I bought it used off Gunbroker.com. The original owner said he only shot twenty-five 00 buck shells through it and then put it in his safe and that he was selling it to fund another project. Said it cycled and ran fine...I believed it, he had a reputable selling history.

The first time I shot it was the day it came in. I put about thirty 00 buck shells through it with 3 failure to feeds and one to eject. I lubed it up and ran fifteen more and it worked fine. But still in my head something kept telling me "Hey this thing isn't fully reliable, nothing near a pump." I kept it beside neglecting my Winchester 1300 Defender who lost it's bedside title when the 930 SPX arrived. So finally I told myself Saturday morning, I am going to do a 75 shot reliability test. Mainly with full power 2 3/4 00 buck and slug shells, maybe even a few 3" shells. To my dismay, the Mossberg failed to shoot a single full magazine without a malfunction. The shell lifter would get stuck on the last shell, it wouldnt chamber a shell and i would get a "click", it wouldn't full cycle and eject spent shells.

I had fully cleaned the gun and oiled it prior to taking it out for the test. I am VERY disappointed in my 930 SPX, I had super high hopes for it. Now I have to get a Mossberg rep on the line and try to send it in for whatever repairs can be done. I added a Mesa Tactical Side Saddle, Tri-Rail sling/flashlight attachment, and a Burris Fastfire red dot believing that this would be my be all end all shotgun :(

Anyone have ideas as to what could be wrong?
 
Try a variety of brands of ammo. I've seen this work for others on similar problems. By the way, I agree, semi-autos aren't as reliable as pumps. Also, try shooting some slugs and see if you have the same problem.
 
Take all the junk off of it first of all, then try it again.

Nothing I added obstructs the cycling of the gun's action. The saddle? It's a Mesa Tactical product not some Tac-Star cheapo. When I first shot it, none of the accessories was on it and it still wasn't reliable.

I spoke to a Mossberg rep and he encouraged me to "break" it in more and if I wasn't happy I could send it in for servicing with a 4-8 week turnaround :eek:
 
EdLaver

I would say maybe take the reps advice and try shooting it some more. When I first had my Mossberg 9200, I gave it a break-in of 100 rounds. Pretty much all field loads from several different manufacturers. Performed perfectly; not a single problem. Then my buddy found another 6 boxes of shells he had leftover from a few previous hunting seasons, and I ran all of them through it too. Again, everything fed and ejected just as it should. So after this 250 round session, I came away very impressed with the 9200s reliabilty and performance. Maybe give your 930 another try with some decent field loads and see where it goes from there.
 
Try better ammo, make sure the shell holder isnt pinching the receiver, and try better ammo and more of it

It should be fine, if it still doesnt feed the last round a simple mag spring replacement would rectify that
 
On my 930 I had problems with light firing pin strikes and a failure to feed the next round when using 3" shells. Chamber would just be empty. No failure to feed on 2 3/4" shells when they went off. About 1 missfire every 25 rounds. I sent it in with an explanation of the problems. About 12 weeks later I got it back. Nothing was changed. It sits in the safe now. Someday I may take it to a gunshow but hate to unload it on someone when I know its not right.
 
Oldnamvet said:
I sent it in with an explanation of the problems. About 12 weeks later I got it back. Nothing was changed. It sits in the safe now. Someday I may take it to a gunshow but hate to unload it on someone when I know its not right.
Contact Mossberg and complain, explain what's going on and make them send you a shipping label, that way they pay for shipping BOTH WAYS, there's nothing worse than a gun sitting in the safe that you can't trust. Make them fix their problems, then if you still want to dump it at least you know that you're not dumping your problems on someone else and, since you had Mossberg pay shipping, it doesn't cost you anything more than your time...
 
I'll second the rep's advice. I've found shotguns in general are typically roughly machined by firearms standards, and it does occasionally take some wearing down the edges to get things working 100%

I've personally got 3 pump action shotguns that I've 'broken in' by spending a nice weekend afternoon watching TV in the living room, while working the pump back and forth a few hundred times.
 
UPDATE:

Ran another 70 shells (Federal, Winchester, Wolf, Remington, 00Buck/Slugs) Seems to be getting a little better, only fails to feed on the last round now.

Just got off the phone with Mossberg again, they are mailing me a replacement spring that they use on the 2010 930 SPXs. After giving the serial #, they said it is one of the earlier SPXs and this new spring is strong and should help in feeding more reliably.

We'll see...
 
Woo hoo!
Fingers crossed. If it works you need to let everyone know with a fresh post maybe!
Al
 
Take the side saddle off. It's a bad design and will cause the gun not to cycle. So I would recommend taking the side saddle off and at least testing to see if that's the problem. It definitely was on mine. I had that same mesa tactical saddle and it would seize up the action when tightened a hair too much or cause the trigger group to be loose if it wasn't tightened enough. It was nearly impossible to find a happy medium that allowed the gun to work properly with the side saddle. Go to a 3-gun gear velcro side saddle; you can get them at dillon precision and they won't screw anything up.
 
I fixed mine. Here was my problems...

I have a 930SPX that was a problem child right out of the box. I was so upset I wanted to sell it, but I thought theres got to be something I can do. I cleaned it, shot it, cleaned it and shot it some more. It would FTE and jam literally more than half the time with any loads I put in it.

Its fixed now, over 400 low brass rounds without a single problem so far.

I finally decided to put the gun under the microscope to see where the problem lied.
I found that the chamber was rough as could be. I ran my finger around in it and I could fell the scratches and grooves in it. Thats always a problem.

Also, I noticed that the extractor wasnt really grabbing the shells worth a crap. It seemed to not reach in toward the bolt face enough. I fixed that too. I had to remove the extractor from the bolt and file down a little area where the extractor met the bolt body. this allowed the extractor to reach in towards the center of the bolt face a little more, ensuring that it has a good bite into the shell casing. This also gives a slight bit more pressure on the shell pushing it to the left hand side of the gun during cycling ensureing good engagement on the ejector, that makes sure that it throws the old out with authority and gets it out of the way for the new cartridge instead of jamming like mine always did. The extractors seem to be like rough cast, or rough forged and that allows for alot of variance between production runs. Some may need help. Re hardened the steel and reassembled.

Lastly I noticed that there are two sets of gas rings in the gas piston. Each one has its own gap. Ensure that the gaps are opposite of each other, just like piston rings in an engine. This will reduce lost compression, or in the case of the shotgun lost gas pressure.

So, polish chamber, alighn gas rings and adjust the extractors attitude and you should be on your way to a happy gun.

I did all this in about an hour, my gun instantly ran like it should after the fixes. Im 100% positive that the three fixes I did directly improved the operation of the gun.
 
I would if all else fails, they tend to pinch the receiver especially the 'no gunsmith' deals when you tighten the screw too much and in a semi auto thats a no go
 
Sorry, old thread I know, but I've been reading up on 930s, and I'm told the last round problem is caused by the mag spring and/or the follower and that changing those and/or getting the higher end Nordic mag extension will help. Did your gun ever become reliable again? I'm considering a 930.
 
Sorry, old thread I know, but I've been reading up on 930s, and I'm told the last round problem is caused by the mag spring and/or the follower and that changing those and/or getting the higher end Nordic mag extension will help. Did your gun ever become reliable again? I'm considering a 930.

The follower in the SPX is a HQ steel follower. I wouldn't change it. There is nothing wrong with the Choate tube extension either. I would change the mag tube spring out for Wolff universal 12Ga spring cut to 28" and bend the cut ends down so they are level with the lower coil.

The SPX needs to be broke in and if you don't want to waste ammo polish the bolt where it rubs in the receiver. Also polish the chamber with steel wool fixed on a wooden dowel rig chucked in a drill. Leave the bolt cocked back while not in use and this will help break in the recoil springs. Don't use any oil on the gas system because it gums things up.


GC
 
There seem to be two simultaneous problems going on with the 930 SPX and the use of the Mesa Tactical side saddle for this shotty:

1) FtF issue on last round- Mossberg is sending out a stronger spring to replace the springs used in pre-2010 manufactured 930 SPXs. You have to call and ask for them to send it.

2) Mesa Tactical side saddle mounting screws may get loose during shooting, allowing trigger assembly to move around (the screws hold the trigger assembly in the receiver), which in turn causes a general FtF issue no matter how many rounds or what kind of rounds (slugs, 00, birdshot) are used.
I talked to MT tech support today, they are sending customers who ask a replacement set of mounting screws and pins that are slightly bigger diameter. As the new pins fit better (tighter), they cannot rock side to side as much as the old ones and therefore cannot rock themselves loose as rounds are fired. They have sent these to some customers having the problem and it has corrected the FtF issue for those customers.

So, if you are having either or both of these problems with your 930 SPX, give both Mossberg and Mesa a call and get your new spring and mounting pins!

I started to experience FtF problems after I installed my 6 round side saddle, so when I get the replacement parts tried out, I'll post here.

Regards,
Doggo
 
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