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3" shells won't cycle

P

pcharden

Copper BB
Hi All! :)

I am new to the forum. Apologies if this specific question has been asked... I have read all other 930 troubleshooting posts and while some seem related, none have been specifically same.

- I have an issue cycling 3" shells only; smaller shells cycle properly, even target loads
- a single 3" shell will cycle properly; more than 1 loaded will fail always
- sometimes the failure is a stovepipe; other times the 2 shells are left parallel to each other
- the bolt is never locked back; typically you can pull backward on the bolt to clear the spent shell and the new shell loads properly

I hope you folks can help me.


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What brand shells?

New gun?

Round count?

Dirty gas system?
 
Hi John! :)

What brand shells?
I have tried:
- Herters Waterfowl #1, 1 1/8, 1550fps
- Kent FastSteel #2, 1 3/8, 1300fps

New gun?
I don't know for sure. I paid $300 in an Armslist deal. S# is AF21XXXX... perhaps that can help with the age???

Round count?
I have sent at least 400 rounds of Herters/Gun Club target loads thru. Also a few boxes of Remington #2, 1 1/8, 1375.

Dirty gas system?
- It is clean.

I have performed the following after reading the troubleshooting threads: recently lightly polished the magazine tube the piston rides on, the piston housing on the barrel, and the chamber

The next place I was thinking was looking at the shell stop; thinking it was releasing the shell ever so slightly early making the new shell collide with the extracted shell before the ejection occurred.

Hopefully I am thinking correctly...

Any help is appreciated..

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Looks like you've eliminated a lot of things already

The 1530 fps shells will have more than enough power to cycle the bolt properly.

You said the gas system is clean, so the only possible I can think to check there since you already polished the surface, is the gas piston installed backwards? Part no. 18 here: https://www.mossberg.com/schematic/?model=930-12-gauge-shotgun-schematic

Reason I asked about that, when I bought my Charles Daly semi auto, it was backwards (and had all sorts of cycling problems). I know that shotgun is not the same as the Mossberg, and the 930 may only be able to put in one way, I don't really know. But my CD wasn't in it right and it caused it issues, so I wanted to ask. It only takes a couple of seconds to check.

When I clicked on the shell stop part at the schematic above, it said it was a factory restricted part.

When I had trouble with my 500 from the shell stop, was different from your description.

When I had problems with it, the shell stop wouldn't move out of the way and it wouldn't allow a shell to be let out of the mag tube. I'd have empty chambers.

Another part that I question, is the extractor springs.

Do you think the shell isn't being extracted and ejected properly and blocking the new shell from feeding right?

If you could just load and shoot 1 shell at a time for a while and make sure that extraction and ejection is OK without dealing with feeding and everything else, may be worth trying to shoot 8-12 times with a single shell just to make sure it's working properly so we can try to diagnose it and eliminate one thing at a time.
 
John A. said:
Looks like you've eliminated a lot of things already

The 1530 fps shells will have more than enough power to cycle the bolt properly.

You said the gas system is clean, so the only possible I can think to check there since you already polished the surface, is the gas piston installed backwards? Part no. 18 here: https://www.mossberg.com/schematic/?model=930-12-gauge-shotgun-schematic

Reason I asked about that, when I bought my Charles Daly semi auto, it was backwards (and had all sorts of cycling problems). I know that shotgun is not the same as the Mossberg, and the 930 may only be able to put in one way, I don't really know. But my CD wasn't in it right and it caused it issues, so I wanted to ask. It only takes a couple of seconds to check.

When I clicked on the shell stop part at the schematic above, it said it was a factory restricted part.

When I had trouble with my 500 from the shell stop, was different from your description.

When I had problems with it, the shell stop wouldn't move out of the way and it wouldn't allow a shell to be let out of the mag tube. I'd have empty chambers.

Another part that I question, is the extractor springs.

Do you think the shell isn't being extracted and ejected properly and blocking the new shell from feeding right?

If you could just load and shoot 1 shell at a time for a while and make sure that extraction and ejection is OK without dealing with feeding and everything else, may be worth trying to shoot 8-12 times with a single shell just to make sure it's working properly so we can try to diagnose it and eliminate one thing at a time.
Click to expand...
Good thots. I had not approached from the other side ...maybe extraction is taking too long...
I will shoot 1 at a time following your thots and report back. I think i will chk chamber polish with my fingernail as well.
Ty for the input.

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I'm just trying to offer some suggestions and hope it helps.

Least this way, you can eliminate much of the problem if it shoots and ejects properly without dealing with everything at once.

Then we can concentrate on something else.

Actually, after you check to make sure it will shoot singles, try loading two at a time. 1 in the chamber and one in the mag, and see if it ejects and loads that way.

One thing that I seem to recall in some early guns is the follower or mag spring caused some issues. Since I don't have a 930 I don't always keep up with them specifically, but I do recall a few posts about it.

Basically, the follower was rubbing and retarding the fresh shell upon firing. Maybe the mag spring was kinked a little in the process. Like I said, I don't recall exactly, But it's easier to try to diagnose an issue one step at a time.

If it shoots and feeds 2 reliably, move to 3 shells and so on.
 
Hi John![emoji4]

Was a bit under the weather lately...

While ill, I did use 000 and polish my chamber again; used a spent shell as a measuring tool.

As discussed, I did go out and shoot 12 singles with mixed results. The 1st, 5th, and 10th stove piped. The 2nd and 4th ejected 1' away; all others ejected >10'. I loaded a pair twice and they cycled properly; for the first time ever.

I got a sample of the shells that stovepiped, ejected 1' and ejected at >10'. Interestingly, they were all slightly different in length. Bad phil... i should have tracked which was which to draw conclusive results; I'll do better next time.

The tolerance between the ejector nub and the chamber is ever-so-slightly shorter than the spent shell length. So it seems like the little bit of difference in shell length might cause an effect like this.

I am going to perform this test again and do a better job at documenting, so i can communicate better data. However, without any further testing/data, I cannot overlook the fact that I have never cycled more than 1x 3" shell at a time, so I think at least part of the cycling issue is still, a break-in issue.

Regards and thanks for the ear... I will report when I have more info...

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Sounds like its leaching gas somewhere. Are you sure you have the piston installed? I actually forgot to reinstall it once when changing barrels and nothing cycled. I felt lime an idiot when I realized what I had done. DOH!

Make sure there are no obstructions, burs, etc in the tube that extends down through the stock. Some grit or resistence there may not allow the bolt to cycle freely.
 
Yeah, if it's not extracting and ejecting a single shell properly, there is something going on.

I truly wish I could have it in my hands to help you test it personally. I believe that it can be worked out.

As MikeD suggested, I would inspect all the surfaces for burrs, rough spots and anything that would cause friction on the moving parts.

While you have the barrel off, can you check to make sure any grease or anything isn't blocking the gas port while you're looking for rough spots?

Here is a good video to show how you can check the gas system.

 
MikeD said:
Sounds like its leaching gas somewhere. Are you sure you have the piston installed? I actually forgot to reinstall it once when changing barrels and nothing cycled. I felt lime an idiot when I realized what I had done. DOH!

Make sure there are no obstructions, burs, etc in the tube that extends down through the stock. Some grit or resistence there may not allow the bolt to cycle freely.
Click to expand...
I have cleaned. It is installed. But I am frequently found to feel like an idiot when I am so sure about anything... I will clean again, re-perform the tests, and report findings...
Ty for the help.

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John A. said:
Yeah, if it's not extracting and ejecting a single shell properly, there is something going on.

I truly wish I could have it in my hands to help you test it personally. I believe that it can be worked out.

As MikeD suggested, I would inspect all the surfaces for burrs, rough spots and anything that would cause friction on the moving parts.

While you have the barrel off, can you check to make sure any grease or anything isn't blocking the gas port while you're looking for rough spots?

Here is a good video to show how you can check the gas system.

Click to expand...
I will clean and retest...
Ty J!

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MikeD said:
Sounds like its leaching gas somewhere. Are you sure you have the piston installed? I actually forgot to reinstall it once when changing barrels and nothing cycled. I felt lime an idiot when I realized what I had done. DOH!

Make sure there are no obstructions, burs, etc in the tube that extends down through the stock. Some grit or resistence there may not allow the bolt to cycle freely.
Click to expand...
Hi M![emoji4]
Just thinking about your and Js thots and trying to align my thinking... is it the inconsistency in operation when shooting singles that makes you point to the gas system?

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If it won't cycle and operate properly when just using a single shell, it won't do better loading more. So, we need to find out why. The suggestions above are some things I would check.

The high brass shells you're using will have more than enough power to function correctly. So, it's not a specific ammo problem. I believe that much is ruled out already. Long as the hulls aren't messed up and dented or deformed or anything.

So, that was the purpose of checking for burrs and the gas system and mag/follower/spring.

When you pull the bolt back by hand, do you feel anything that feels rough or unusual?

If you load the mag all the way up with shells and cycle the bolt back by hand until it is empty, do you notice the shells coming out of the mag tube sluggishly or anything?

Be careful working with loaded ammo, but it is something I would check for.
 
John A. said:
If it won't cycle and operate properly when just using a single shell, it won't do better loading more. So, we need to find out why. The suggestions above are some things I would check.

The high brass shells you're using will have more than enough power to function correctly. So, it's not a specific ammo problem. I believe that much is ruled out already. Long as the hulls aren't messed up and dented or deformed or anything.

So, that was the purpose of checking for burrs and the gas system and mag/follower/spring.

When you pull the bolt back by hand, do you feel anything that feels rough or unusual?

If you load the mag all the way up with shells and cycle the bolt back by hand until it is empty, do you notice the shells coming out of the mag tube sluggishly or anything?

Be careful working with loaded ammo, but it is something I would check for.
Click to expand...
Hi J![emoji4]
I think I understand. Currently 2 3/4 everything, including target loads operate properly. The 1500+fps, 3" shells I am shooting are cheap Herters shells.
The action is smooth (as far as I can tell) and cycles a full magazine completely.
I have disassembled and cleaned again but did not check for burrs, so I will do so.
Thanks a bunch...

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Take a look at this video from BigDaddyHoffam1911. His 930 is doing exactly as you are discribing and the whole problem was nothing more than the brand of ammo he was using.
 
Saw that video along with a lot of others right before I bought mine. Bought my 930spx anyway. Brand of ammo does make a difference. The 930 is the best bang for a shotgun on the market today. An is in fact a very reliable semi-auto shotgun.
 
I also watched a video by that guy last night concerning another semi auto 12 that I liked.

 
I suspect ammo.;)
http://65.19.191.220/forum/viewtopic.php?t=19321&view=next&sid=3d19e29c16a50661522ef68f2e237029

My 930 gobbles Suprema trap & skeet up to 00 like the chubby kid at the icecream bar, which is about as cheap as I've tried. European ammo I've generally found to be iffy. A friend who was able to tour the Benelli factory back in the early '90s asked one of the engineers about the thin sport-weight barrels on the M1-M3 tactical guns, and the problematic issue of shell carriers. The response: "You Americans shoot your guns too much!":confused:
 
The OP hasn't replied since January 2nd, so hopefully the problem was found and simple. That said, I typed most of this up before noticing the original post date and thought I would post anyway for anyone else running into similar problems.

Since it is a used gun with an unknown number of rounds, make sure your magazine spring hasn't been trimmed short or is otherwise weak. When you step up to 3" shells the recoil and heavier shell column (in the magazine tube) reacting to the recoil can change the reliability of shells feeding from the tube. Something to check that doesn't always occur to everyone. Make sure you are solidly behind those 3" rounds too.

Since 3" shells do a fine job of utilizing the secondary gas system, make sure that your secondary has a good seal. Again, with a used gun it is hard to know what has been done. If the previous owner had a burr in the secondary gas system and ran a lot of hot loads it may have scored up the magazine tube under the secondary. If this was 'repaired' by polishing with steel wool the tube is now smaller in diameter, potentially out of round and may be quickly leaking the gas as soon as the secondary opens up a bit. Pitting from rust that was similarly 'repaired' can have the same effect on the seal of the secondary gas system. A replacement magazine tube is often the fix for gas system issues. If you end up doing this, get the JM Pro version if you don't already have it. The rust issues are all but eliminated and it cleans up easier.

I didn't see mention of barrel length anywhere in the thread. A hotter load that is heavier will usually improve cycling, but a hotter load that is only faster (with the same weight like the Herter's) can sometimes make it worse as the dwell time for the round is shorter with a faster load. If your gas system has problems the malfunctions will sometimes show up even more with a faster load as the gas pulse is so much shorter.

I know that sends you in several different directions, but they are ones it doesn't sound like have been explored yet.

Let us know how it goes.

Thanks!

William

http://www.OR3GUN.com
 
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