What has happened to the Mossberg 930?

[rtp]

Another match with several JMs this past weekend, no issues with the (I think 4 total) JMs.

Had a VersaMax become a single shot; go figure.

[IainC]

I ran my 930 JM Pro for a year, tried numerous fixes, but could not get it to run 100% reliable.

it ran great until it got dirty and then it would jam repeatedly, it only took 70-80 rounds before there was so much crud on the magazine tube that it would slow down.

It could just be the very dirty UK shot shells, but my next shotgun is going to be inertia.

Edited January 28, 2014 by IainC

[openclassterror]

We had 2 different JMs at our local matches show up with the same problem, which was shells hanging up in the mag tube. One guy sent his back to Mossberg, and I think it was only gone 9 days total. Bummer was the $60 it cost him to ship it back, by the time he properly insured it. The other guy polished the step between the extension and the mag tube, and solved his own problem. I talked to one of the Mossberg tech reps at SHOT, and he said there have been some fitment issues with the Nordic extensions they use on the JMs, and they have just sent out replacement parts to some customers to keep them from having to ship the whole gun back. Seemed like they have seen a few with the same problem. At least they have ID'd the problem and are trying to make it right. As far as their customer service goes, I always had decent experience with them back when I did general gunsmithing, and they replaced lots of parts for me under warranty. Can't tell you how many rusty, abused pump guns got new ejectors in my shop!

[Tomas]

bought my JM pro about a year ago it ran okay for about 1 match after which I replace the mag spring along with the follower with a NC and it promptly became that "F" ing POS for the last 3 matches with a consistent failure to feed "BUT" it shot slugs to the crappy factory frontsite POA so I have persevered with referring to the troubleshoots that everyone has come up with, also had jeff from C-Rums weld up my lifter which helped immensely and he also gave me the tip of polishing the bolt stop which has caused it to start working for me manually without having to wack the bolt handle to get it to release a shell from the tube and it also went 2!! stages without trouble. I also feel Mossberg really screwed the pooch on this just like the SPX when it first came out and after reading the best case scenario's with mossies CS I figured it best to not even try contacting them. I feel the 930 JM Pro is basically an over priced parts kit that may or may not run out of the box , but the reason I bought it was my buddy would not sell me his M1 super 90 that I had been borrowing for the last 3 years. can't say that I would recommend it as a GTG out of the box but I have met several other folks with "other" 930's and they have 0 complaints

Nordic states on their website that the follower isn't for mossbergs. Could be your issue. Also what length is your spring cut?

so far the follower has cured the shell hang up between the extension and mag tube. got my spring cut down to 10" been running shells through it manually and it now consistently will feed as long as I run it with the normal alacrity one would normally use. spent the last 2 weeks manually racking it till I have at least 1000+ cycles with hang ups getting fewer and fewer still want to got to the range and run at least 50 rounds through to make sure .

[rtp]

We had 2 different JMs at our local matches show up with the same problem, which was shells hanging up in the mag tube. One guy sent his back to Mossberg, and I think it was only gone 9 days total. Bummer was the $60 it cost him to ship it back, by the time he properly insured it. The other guy polished the step between the extension and the mag tube, and solved his own problem. I talked to one of the Mossberg tech reps at SHOT, and he said there have been some fitment issues with the Nordic extensions they use on the JMs, and they have just sent out replacement parts to some customers to keep them from having to ship the whole gun back. Seemed like they have seen a few with the same problem. At least they have ID'd the problem and are trying to make it right. As far as their customer service goes, I always had decent experience with them back when I did general gunsmithing, and they replaced lots of parts for me under warranty. Can't tell you how many rusty, abused pump guns got new ejectors in my shop!

That's interesting they're acknowledging this one, although it was already called out by owners as something to check for (mismatch from tube to extension), and possibly correct yourself, as you mentioned.

I also expect the OE follower may add to the issue slightly. Replaced mine with an RCI follower (long, but hollow, spring compresses inside), did some minor polishing of the full mag + extension, have never had a hangup in the mag.

Would sure be nice to see Mossberg's customer service be a bit more open (acknowledging issues w/customers), and making parts more easily available, for those that have/do run into issue, though.

[Tummytuck]

930s do not always hand cycle reliably because they use a bit of inertia from the rounds in the magazine to cycle. The weight of the ammo actually moves forward when fired. I love mine,shoots everything from deer slugs to 1100 fps federal birdshot reliably. Just cut mag spring 12 to 14 inches past mag tube extension and it works! Tried a couple of turkinellis before I got sick of them,nothing but issues,(Citadel and SDS), good thing I got them cheap.