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Mossberg 930 Autoloader Troubleshooting

Is this normal?

I have a 930 SPX that I bought last Oct, and love it, performs flawlessly. I had to send the barrel back, though, for the dreaded canted front sight. While waiting for the warranty repair, I decided to purchase the 28" smooth barrel so I could use it for sporting clays. Looks a little funny with the extended mag and pic rail, but hey, it works. Anyway, after shooting a round of clays, I took it apart to clean it, and noticed the gas piston was not seated back in the gas cylinder, but was jammed partially extended. I've cleaned and shot the gun a few more times, hoping it would loosen up, but it is just darn snug in there when the gun is assembled. The piston slides easily over the mag tube, and out of the gas cylinder, when the gun is disassembled, but binds when put back together. Funny thing is, it operates perfectly, never failing to extract or to load a new shell.

Question: should I be able to move the piston out of the cylinder with finger pressure, and should the return spring bring it back into the cylinder with no additional assist? If this is not operating correctly, any thoughts on what could be wrong? Could it be that the gas cylinder and the magazine are not parallel? I spoke with Mossberg, they want me to send it back, but I'm still waiting for the short barrel, I don't want to send the gun out if this is "normal". Thanks!
 
I have a 930 SPX that I bought last Oct, and love it, performs flawlessly. I had to send the barrel back, though, for the dreaded canted front sight. While waiting for the warranty repair, I decided to purchase the 28" smooth barrel so I could use it for sporting clays. Looks a little funny with the extended mag and pic rail, but hey, it works. Anyway, after shooting a round of clays, I took it apart to clean it, and noticed the gas piston was not seated back in the gas cylinder, but was jammed partially extended. I've cleaned and shot the gun a few more times, hoping it would loosen up, but it is just darn snug in there when the gun is assembled. The piston slides easily over the mag tube, and out of the gas cylinder, when the gun is disassembled, but binds when put back together. Funny thing is, it operates perfectly, never failing to extract or to load a new shell.

Question: should I be able to move the piston out of the cylinder with finger pressure, and should the return spring bring it back into the cylinder with no additional assist? If this is not operating correctly, any thoughts on what could be wrong? Could it be that the gas cylinder and the magazine are not parallel? I spoke with Mossberg, they want me to send it back, but I'm still waiting for the short barrel, I don't want to send the gun out if this is "normal". Thanks!
 

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arcsound said:
I have a 930 SPX that I bought last Oct, and love it, performs flawlessly. I had to send the barrel back, though, for the dreaded canted front sight. While waiting for the warranty repair, I decided to purchase the 28" smooth barrel so I could use it for sporting clays. Looks a little funny with the extended mag and pic rail, but hey, it works. Anyway, after shooting a round of clays, I took it apart to clean it, and noticed the gas piston was not seated back in the gas cylinder, but was jammed partially extended. I've cleaned and shot the gun a few more times, hoping it would loosen up, but it is just darn snug in there when the gun is assembled. The piston slides easily over the mag tube, and out of the gas cylinder, when the gun is disassembled, but binds when put back together. Funny thing is, it operates perfectly, never failing to extract or to load a new shell.

Question: should I be able to move the piston out of the cylinder with finger pressure, and should the return spring bring it back into the cylinder with no additional assist? If this is not operating correctly, any thoughts on what could be wrong? Could it be that the gas cylinder and the magazine are not parallel? I spoke with Mossberg, they want me to send it back, but I'm still waiting for the short barrel, I don't want to send the gun out if this is "normal". Thanks!

um wheres your spring brotha ???

Your suppose to have a before that slider with the 2 poles ...
 
Thanks. I didn't realize the spring was not installed in the picture, but that is not the problem, I install the spring when I reassemble the gun. The problem is the gas piston is "wedged" or stuck partially sticking out of the gas cylinder, as shown. I'm assuming that these parts are normally much more mobile, and that the spring you mentioned should be strong enough to reseat the piston in the cylinder, which it is not in my case. I have to dismantle the barrel to reseat the piston in the cylinder. So.....if someone could verify that this is not correct, I will send it back to Mossberg.
 
arcsound said:
Thanks. I didn't realize the spring was not installed in the picture, but that is not the problem, I install the spring when I reassemble the gun. The problem is the gas piston is "wedged" or stuck partially sticking out of the gas cylinder, as shown. I'm assuming that these parts are normally much more mobile, and that the spring you mentioned should be strong enough to reseat the piston in the cylinder, which it is not in my case. I have to dismantle the barrel to reseat the piston in the cylinder. So.....if someone could verify that this is not correct, I will send it back to Mossberg.
Arcsound;
That's definitely wrong... the gas piston is to move freely sometimes it would just fall out when you take out the barrel. I would contact Mossberg if you cannot unwedge it. Now I wouldn't suggest trying to fix it your self because you could scar the inside of the tube and might not seat correctly for the piston to work.
 
Thanks again. As you describe, the gas piston is not bound once the barrel is removed from the receiver, and it also moves freely (no fricton) over the mag tube (when barrel removed), but when assembled, i.e. everything installed, including barrel in receiver, the gas piston is very hard to move out of or back into the gas cylinder. This is what is making me think there is an alignment problem between the gas cylinder, which came with the new barrel, and the mag tube, which is attached to the receiver. I never noticed if this behaviour occurs with the original short barrel, which of course, would be a different gas cylinder, and which I can't check since the short barrel is still with Mossberg having the sight aligned.
 
arcsound said:
Thanks again. As you describe, the gas piston is not bound once the barrel is removed from the receiver, and it also moves freely (no fricton) over the mag tube (when barrel removed), but when assembled, i.e. everything installed, including barrel in receiver, the gas piston is very hard to move out of or back into the gas cylinder. This is what is making me think there is an alignment problem between the gas cylinder, which came with the new barrel, and the mag tube, which is attached to the receiver. I never noticed if this behaviour occurs with the original short barrel, which of course, would be a different gas cylinder, and which I can't check since the short barrel is still with Mossberg having the sight aligned.
Mine is pretty tight as well... Its suppose to be to have a nice seal for the piston. If you look @ the piston it self. It has 2 metal rings, those are kinda like piston rings you would find in a piston drive motor. Its not suppose to not move freely when everything is put together which creates a type of seal in the piston camber. If did move you would have issues with it feeding because the pressure to send it back is leaking else where. This is my own diagnosis and how I understand the gas piston to work...
 
Mossberg took care of my 930 tactical

I got a 930 tactical in trade about a month ago. It is the first time I've gotten a lemon in a trade. All I have read stated the 930 was a very reliable weapon and I have been wanting one for a few years. Well I traded and M&P compact for one and was all excited when I went to the range. Unfortunately I had multiple issues every few rounds. Failure to extract and to eject mostly with all types of ammo. The weapon was very clean when I got it and the previous owner said he only fired 10 rounds through it before trading it to me. That should have been a clue because when I tried to field stripped it all the way down, there was a scrap in the magazine tube across the threads and I could not get the barrel off. Not sure if it was bought that way or not.

So I boxed it up and sent it to Mossberg with a letter stating my issues. My gun also came with a rail attached that made the bead sight useless so I asked Mossberg to install screws without the rail. Well I got my shotgun back Saturday while I was out of town. Today I finally got to tear it down and shoot it. It appears Mossberg replaced the magazine tube, the recoil spring and gas piston ring according to the paper in the box. They also installed flush fitting screws in the receiver.

I took it out to the range this morning and fired about 50 rounds of mixed ammo without a hitch. I used Winchester number 4 buck, Remington Dove loads and some reduced recoil slugs. Everythinig functioned fine and I couldn't be happier now that I have a working shotgun. Mossberg definately took care of me. I paid 21 dollars to ship my shotgun and they replaced everything else free of charge. I can't sing there praises enough and just wanted to let everyone know. David
 
Re: Mossberg took care of my 930 tactical

Hmm ... all that at no cost on a used gun? Maybe I need to send in my SPX. I just cannot get that thing to feed reliably. Pretty much every magazine produces one failure to go into battery.

How long did Mossberg have your gun? Do you have any contact info that might be helpful or did you just ship it to their customer service address? Appreciate it.
 
Re: Mossberg took care of my 930 tactical

Thanks for sharing your experiences with Mossberg! It is great to hear that they took care of you and that you now have a fully functional Mossberg 930 like it should have been from the start. :cool:
 
Re: Mossberg took care of my 930 tactical

Mudinyeri said:
Hmm ... all that at no cost on a used gun? Maybe I need to send in my SPX. I just cannot get that thing to feed reliably. Pretty much every magazine produces one failure to go into battery.

How long did Mossberg have your gun? Do you have any contact info that might be helpful or did you just ship it to their customer service address? Appreciate it.


I was going through the same thing as you with a failure every 5 to 10 rounds. I looked up on the website and Mossberg states to just mail it in with a note. Not wanting to just send my shotgun off to parts unknown, I called Mossberg and was told the same thing and the website. So I wrote a detailed letter of the problems I was having with my contact info and shipped it off about a month ago. I did mail it priority with delivery confirmation. Once it arrived I was going to wait a few weeks and call on the progress. Well last week I was out of town last week and my wife called me on Saturday. The first thing out of her mouth was, "Did you buy another gun?" So my shotgun was gone about 3 weeks including my priority USPS mail and they returned it Fedex to my door. Real nice of them I think. Also I put another 25 round through it before I left work and it eats slugs with ease. I would suggest sending it out if you have a problem. Good luck. David
 
Re: Mossberg took care of my 930 tactical

Thanks, David. I'm going to do just that. I hope my experience is as positive as yours.
 
detent ball stuck in safety indicator

hello all.

well like the title says, the safety detent ball is stuck in the red "fire" indicator. i removed the safety to do a little part swap, and there it was. stuck in that little divot. and for the life of me, it will not come out! my safety worked fine before. i've never had any problems with it. so i have no idea why this has happened, or how to fix it.

i did read on shotgun world of one other person who had this problem, but he never came back to elaborate on if/how he resolved the problem, and i think it was a thread from around 2007. so would any of you folks here have any advice? i'd really appreciate it.

brad
 
Re: detent ball stuck in safety indicator

Use a thin very sharp awl (or sewing needle) placed between edge of ball and receiver.
Tap with hammer. Dress receiver with a needle file.
(DO NOT HIT IT HARD!)
You might want to do this within a plastic bag so the ball doesn't fly into
parts unknown.

(Bag the stock, tie it closed aft of trigger, push awl or needle
thru bag. 1 sharp tap should do it)
 
Re: detent ball stuck in safety indicator

excellent idea. unfortunately it did not work. that thing is really in there and i'm dumbfounded. it makes no sense. there was no gunk or buildup present that could have made it stick like this. i just don't get it.

thank you anyway for the advice ladytech.
 
Re: detent ball stuck in safety indicator

sounds very stuck. not even a rare earth magnet will pull it out? if the needle and hammer trick didn't work, then i'm not really sure what to suggest to keep from damaging (albeit slightly) the receiver and/or detent ball.

i don't know... perhaps shoot some wd-40 in there or better yet, pb blaster? a shot of compressed air from an air nozzle at 110 psi (without losing the ball into oblivion)?
 
Re: detent ball stuck in safety indicator

This was interesting so I wanted to know why, as I own a 500C and don't want it to happen to me.
Close inspection I found Mossberg uses a wax type coloring for the red dot. Now I realize why you can't get the ball out as it is the same size as the detent and is a little deeper than the drill point or whatever they use in manufacture. The wax holds the ball securely.

So here goes the fix I used. You need to be "good with tools" and take care not to do more than necessary. Using a small drill ( #55-60) drill a hole approx 1/32 deep at the rear edge of ball and detent hole.
A sharp awl or pin will pry it out. When clear use a dremel and small round bit dress up the detent to an oval.
1 drop of nail polish 9 (any color red I'm sure your wife or girlfriend has) to finish.
If you just want to prevent it from ever happening- dremel the detent to an slight oval and color.
You can do this without any disassembly. If you work carefully you will not even notice the work.
If you scratch it, use a touch up pen. Good luck!
 
Re: detent ball stuck in safety indicator

actually after i came on here and said it didn't work, i gave your idea another try. except i really smacked it a good one. and it did work. the safety looks a bit rough now, but it functions properly. thanks for the help.

bradley
 
Re: detent ball stuck in safety indicator

Thanks for the update; glad you were able to free up the detent ball from the safety indicator.
 
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