Another 930 SPX Tube Capacity Problem

[1sloXKR]

Hello All,

I bought a brand new 930 SPX . I am new to shooting in general and have only shot pistols and AR rifles before. The 930 SPX was much less expensive ($769) compared to other similar semi-autos from Beretta & Benelli ($1000 plus).


Immediately, I noticed an annoying issue where the forearm (foregrip) would move or wiggle slightly. I tightened the magazine tube extension, which helped but did not completely cure the annoyance. Or3gun seems to make a product that fixes this for about $40.


At the range, I began loading 2.75” shells to test out. Advertising a capacity of 7, I was surprised to only be able to fit 4-5. I tried troubleshooting by unscrewing the factory magazine extension tube and screwing it back in again.


I eventually was able to load 7 shells, but not before multiple attempts at loading/reloading. After that, I tried to replicate and could not get 7 in the tube again.


There was also a single FTF during my test (20 slugs fired), but I did not pay attention to the exact problem due to my overall frustration with the tube capacity issue.


Looking at older Forum posts, this seems to be a known issue with the 930 SPX going back ten years. I am very disappointed that my brand new shotgun isn’t working as advertised and will be calling Mossberg tomorrow morning to see what they will do to address this.


I won’t be cutting the spring, replacing the follower, etc. on a brand new gun that should work as advertised to begin with. I’ll keep this thread updated with what comes next.

 

[Jmm14534]

Interesting first experience’s with your Mossy. Please keep us informed about all the possible remedies. I know they are out there. You need to be patient and deliberate on the modifications.

 

[MikeD]

I've never had a gun from any manufacturer that didn't have a little forend wobble, even with the OR3GUN parts ( though it did help a little)

Did you clean the gun thoroughly? My 930 came with a lot of grease which renderred it single shot in cold weather. Removing the factory grease and reoiling solved that issue

The FTF could be a fluke, ammo, dirty gun or you just need to break in the springs a bit. May be easier to diagnose if it occurs with regularity or with specific ammo. Could also be a buffer spring tension issue. OR3GUN parts can fix this as well if the issue persists past break in or if you regularly shoot lighter ammo.

As far as magazine capacity it could be multiple things:

The transition where the mag tube extension screws on could have a lip/burr that is causing the spring/follower/ammo to catch.

The spring may need to be trimmed as there is not enough soace for it to compress. This is often an issue when replacing a spring.

The ammo you are using. Some rounds are longer, some are shorter, this could account for a difference. Try different ammo brands. The 2.75 in length is the hull length after firing corresponding to internal dimensions of the barrel.

You could have dirt in there that is causing an issue.

The follower could be canting a bit under pressure and causing excess resistence. Do not oil these components as it attracts dust whick causes issues.

I know its a new gun but they all have a break in period where springs soften a bit and parts wear in. Its unavoidable.

These are the top things I would check

 

[1sloXKR]

I didn’t clean the gun before shooting it for the first time. The FTF will be investigated once the capacity issue is solved and I go to the range again.

I tried two different ammo varieties and after trying and trying, 7 rounds did fit one time. I could not replicate that and it returned to 4-5 max.

Mossberg will be mailing me a new follower and possibly other parts to try and fix the problem myself. If that doesn’t work, I will mail the shotgun back for review.

 

[MikeD]

Good luck, keep us posted.

 

[1sloXKR]

I received the parts from Mossberg today. The address had an error, but luckily Fedex caught it and delivered it to my correct address.

Mossberg sent a 940 JM PRO Spring, 940 JM PRO Follower, and 930 SPX white cap. I’m not sure if that was intentional or another error? I gave the representative my serial number.

In any case, the new parts made the problem worse and I could only fit part of the 7th shell. I tried the new spring with old follower and it “hung up” a bit more but I still could not get the 7th shell in.

Originally, I tried 2.75 shells and slugs, but I only had shells to test this time.

I am very disappointed and will try to work this out with Mossberg tomorrow.

 

[Jmm14534]

I am not familiar with the SPX model but I have 2 M930 shotguns. My M930’s do not have the “white cap”. What is this part for/do? Does it go on the follower end of the spring or the non follower end of the spring?
Both my M930’s have a little fore-end wiggle. I just tighten the nut down and it does not bother me.

 

[1sloXKR]

The white cap goes at the end of the spring hitting the magazine extension tube opposite the follower end.

I’ve been playing around with the parts I received after confirming with a Mossberg representative that the 940 Spring and follower are correct for my 930 SPX.

I bought Winchester brand shells that are twice as expensive as the Buffalo brand shells, and have a star crimp at the end.

The stock configuration with original spring and follower still hangs up when trying to load 5th/6th round of both shell types.

The new JM Pro spring/follower still does not let me load 7 shells as advertised, even with shorter Winchester shells.

The old spring/new follower barely allows me to fit 7 Winchester shells. The transition from magazine to extension tube feels smoother with the new follower.

The new slightly longer spring with old follower allows me to readily fit 7 Winchester shells and has not given me problem yet with fitting the last few.

I don’t know what to make of this. I’ll test the gun out on Saturday to see if it feeds without issue.

Unless there are 2 3/4 shells shorter than Winchester’s star crimp, the set of replacement parts sent by Mossberg would not have fixed this problem.

 

[MikeD]

Try removing the white piece. Its not needed and could be causing the issue I've had several extensions in multiple model guns and have never seen that part.

 

[Jmm14534]

Try removing the white piece. Its not needed and could be causing the issue I've had several extensions in multiple model guns and have never seen that part.

I agree with Mike D. Get rid of the white piece. If it’s there to protect the end on the magazine extension then ditch it and just file down the end of the spring so it has no sharp edges and bend it back and out of the way.
Also make sure the magazine extension is not out of line with the magazine tube. They should share the same center line.
Pics are worth a thousand words!

 

[1sloXKR]

The part is a small plunger/stop that goes into the last coil before spring touches the magazine extension.

The 930 SPX, brand new, came with the white cap installed. I was sent an extra white cap to be used with my new follower and spring from the factory.

I don’t want to modify, change, or remove parts on the principal that a new firearm, car, toaster, or any other mechanical device should work as advertised (reliable 7+1 feed) when new.

 

[MikeD]

@1sloXKR I hear what you are saying and I see your point.

But ..

Magazine capacity is a fickle thing that sadly sometimes needs some tweaking. Every gun is not going to work flawlessly with every ammo.

You arent out anything by trying some options.

 

[Jmm14534]

Not for nothing @1sloXKR but tinkering with your shotgun is one of the privilege’s that comes with ownership. Just my $0.02.
Living in New York State the first M500 pump gun I ever purchased was advertised as an 8 + 1 gun. The shotgun had a wooden dowel in the magazine tube to limit it to 2 + 1 out of the box.
I’ve made changes to each of my Mossy’s to make them capable for their intended role as well as make them mine. I actually purchased my first M930 specifically to see if the negative YouTube reviews where correct. They weren’t.
I get the out of the box customer satisfaction argument. As customers we deserve this. In my dealings with Mossy service they have been great as I think you’ve experienced.
Good luck. I wish you a good range day and hope you sort out your issues. Keep us posted and send pics!
There is another very similar post on this website and it looks like they have sorted things out. If they did you can too.

 

[Rob72]

I don’t want to modify, change, or remove parts on the principal that a new firearm, car, toaster, or any other mechanical device should work as advertised (reliable 7+1 feed) when new.

I certainly understand your thinking and expectation; however, especially with Mossberg (and Ruger) it is not realistic.

The 930/940 design is an amalgam of well established and functional designs cobbled together (e.g., Win SPX, Benelli M1, Beretta 1200/1300, Browning). You can literally purchase OEM parts for the referenced guns and generally plug-n-play in the 930, or do so with minimal fitting.

I understand you may not want to, but if you're so inclined:

Buy a 3 arm brake cylinder hone from AutoZone or O'Reilley's. Using cutting or penetrating oil, hone the inside of your mag tube & extension. Go back and spend extra time chamfering the mouth of the mag tube and inside the extension where it steps from threads to straight wall. Clean and lightly lube (I use dry-lube).

Lastly, get a longer cupped follower, such as the Nordic aluminum or GG&G stainless Beretta 1301 models. These transition the tube/extension gap much better and won't catch the spring as some "tailed" followers will.

930s are generally good guns, but they are starters or base guns, not a prime OTB platform.

Edit: I could not remember the site for the followers I use, but was able to find it. I prefer stainless, but in aluminum, these are the best I've used: https://www.hfd2.com/defender

 

[Keniff536]

Here are a few things that might help. I also recently bought the 930 SPX and love it. I also experienced the magazine capacity issue, but I realize no two guns are exactly alike so I started to experiment\tinker. I found that the brand of 00 buck I was using would only allow 6 shells in the tube, but when I switched to slugs(a different brand), I could load seven every time. Both shells are advertised as 2.75. But look at the attached picture, that small amount in size makes the different. This is with the original follower and the white plug at the end of the mag spring. So shell size can resolve this issue in "my" case. Throughout my experimenting I installed the GG&G follower(see pic) to address the mag capacity issue, but after I did, I couldn't even get the seven slugs in the magazine. I plan to generally run 00 buck, so I'm going to shop around for some that are shorter than the ones I'm currently using. And to be honest, not having the one less shell doesn't bother me that much as long as the gun runs without malfunctions, which it has.
And here is something else I discovered, after installing the GG&G flashlight mount, it fixed the fore end wobble. That little thickness on the ring was just enough to make it tight. So keep tinkering, it will help you learn "your" gun like the back of your hand.

Here are my mods, I think I'm done. 5 shot velcro side saddle, NDZ safety, GG&G flashlight mount, SOE single point sling and GG&G follower(may go back to the original)

 

[Coyote56]

Here are the replacement parts from OR3GUN, GG&G, and Nordic Components I installed on my Mossberg 930 SPX. Still holds just 6+1 shells, but I will agree shortening the spring just a tad should solve that issue. As I’m selling the 930 I replaced all the parts shown with OEM. I will be putting these up for sale sooner than later.