Solvability Posted August 19, 2013 Share Posted August 19, 2013 (edited) Mossberg 930 has continued with intermittent issues - I believe I have it figured out - the gun was not going into battery - the hammer would fall but the firing pin was blocked from hitting the primer (a good thing). So I went through the history of the gun - it worked until I put in the 24 inch barrel then the problem started - so looking at the original 18 inch barrel I find the gas piston slides relatively easily in and out of the gas block when mounted on the gun, but on the 24 inch barrel it was quite stiff - I believe the 24 inch barrel has the gas block tilted slightly high at the breech end which is trapping the gas piston assembly. The right answer is just to send the 24 inch barrel to Mossberg and get them to replace it - or I may try to polish out the mag tube some to give it the .001 or so clearance that it needs to align - it is a very small misalignment but enough to make me and the gun unhappy.I am not very impressed with the build quality of the Mossberg (the design yes, the build quality no).The 18 inch barrel works fine - it is just too short for all of the stages we run and it is a fixed cylinder choke. Edited August 19, 2013 by Solvability Link to comment Share on other sites More sharing options...
rangerguy Posted August 19, 2013 Share Posted August 19, 2013 I know a couple of guys say that there gun developes a burr on the locking lug that prevents it from fully going into battery. Not sure if this is your problems but might be a start. Link to comment Share on other sites More sharing options...
Onagoth Posted August 19, 2013 Share Posted August 19, 2013 (edited) My 930 has performed extremely well for the 1 or 2 years that I shot it. I had it fail once during a match which was because I didn't clean the gas rings/system in forever (totally my fault)....crusty would be a good word to describe it. Having said that, I recently upgraded for an M2. Edited August 19, 2013 by Onagoth Link to comment Share on other sites More sharing options...
Thecelt Posted August 19, 2013 Share Posted August 19, 2013 id send the barrel back. polishing would probably work but if you polish it and it doesnt work then mossberg might not take the barrel back. i agree with you that the design is solid, but mossbergs quality control is lacking. jmost 930's run great and reliable with simple cleaning of the piston system. but there are some that just have continual problems which is entirely related to quality control. Link to comment Share on other sites More sharing options...
usmc1094 Posted August 19, 2013 Share Posted August 19, 2013 Shot my 2nd match with the 930 JM yesterday and it only made it through 1 of 4 stages. I was haveing failure to ejects that were bad enough to lock the gun up so tight that the range gunsmith had to take it to clear it before we could move on, and that was on the 1st stage. I'm going to blame the Wal-Mart bulk ammo. The smith said it looked like the cases had over expanded, jamming them in the chamber. Makes for a very long day. Link to comment Share on other sites More sharing options...
Nuke8401 Posted August 19, 2013 Share Posted August 19, 2013 I believe the 24 inch barrel has the gas block tilted slightly high at the breech end which is trapping the gas piston assembly. So I assume you came to the conclusion that the piston in sticking by: - assembling the gun without the forend and hold the barrel in place. - cycle the piston by hand, it should snap back to the full forward position (your post indicates yours does not) - try twisting the barrel to see if there is a sweet spot where the piston returns freely. If there is a sweet spot you may be able to clean, polish and reassemble with the sweet spot in mind and improve the function. As far as polishing the mag tube, I believe the ring to mag tube clearance/seal (piston ring ID) is just as important ring to cylinder (piston ring OD) so I would not seek to open either of these clearances too much. Link to comment Share on other sites More sharing options...
Solvability Posted August 19, 2013 Author Share Posted August 19, 2013 I believe the 24 inch barrel has the gas block tilted slightly high at the breech end which is trapping the gas piston assembly. So I assume you came to the conclusion that the piston in sticking by: - assembling the gun without the forend and hold the barrel in place. - cycle the piston by hand, it should snap back to the full forward position (your post indicates yours does not) - try twisting the barrel to see if there is a sweet spot where the piston returns freely. If there is a sweet spot you may be able to clean, polish and reassemble with the sweet spot in mind and improve the function. As far as polishing the mag tube, I believe the ring to mag tube clearance/seal (piston ring ID) is just as important ring to cylinder (piston ring OD) so I would not seek to open either of these clearances too much. Yep - exactly. Link to comment Share on other sites More sharing options...
toothandnail Posted August 19, 2013 Share Posted August 19, 2013 (edited) The 18 inch barrel works fine - it is just too short for all of the stages we run and it is a fixed cylinder choke. Why not, have the 18 threaded for chokes? 18" is all I've ever run in 3gun, heck we were breaking clays consistently at 65 yds with a Xfull choke. Shot my 2nd match with the 930 JM yesterday and it only made it through 1 of 4 stages. I was haveing failure to ejects that were bad enough to lock the gun up so tight that the range gunsmith had to take it to clear it before we could move on, and that was on the 1st stage. I'm going to blame the Wal-Mart bulk ammo. The smith said it looked like the cases had over expanded, jamming them in the chamber. Makes for a very long day. Winchester bulk pak ? , we've had that same problem for quite some time, does the same in my Benelli , 930, MKA 1919, never had a lockup that bad, but routinely they would come out WITHOUT most the lip for the extractor to grab, Yes the SWELLED that much, or the "brass" was split. Quit buying Winchester about a year ago, Win AA's NO problems Edited August 19, 2013 by toothandnail Link to comment Share on other sites More sharing options...
usmc1094 Posted August 19, 2013 Share Posted August 19, 2013 Winchester bulk pak ? , we've had that same problem for quite some time, does the same in my Benelli , 930, MKA 1919, never had a lockup that bad, but routinely they would come out WITHOUT most the lip for the extractor to grab, Yes the SWELLED that much, or the "brass" was split. Quit buying Winchester about a year ago, Win AA's NO problems Thats good to know Link to comment Share on other sites More sharing options...
Nickoli Posted August 19, 2013 Share Posted August 19, 2013 Shot my 2nd match with the 930 JM yesterday and it only made it through 1 of 4 stages. I was haveing failure to ejects that were bad enough to lock the gun up so tight that the range gunsmith had to take it to clear it before we could move on, and that was on the 1st stage. I'm going to blame the Wal-Mart bulk ammo. The smith said it looked like the cases had over expanded, jamming them in the chamber. Makes for a very long day. Ive ran about 600 rounds through mine now with Wallmart bulk packs. I shoot Federal though and have not had any cycling issues. I did have a round not fire yesterday on one of the 3GN classifiers, cycled the bolt by hand, kicked out the shell and I inspected it after the stage. It did not have any striker mark on it at all. This is the first time this has happened to me. Ill be placing an order this week for the 10/22 extra power spring and hope it gets here before the shotgun match this Sunday. Link to comment Share on other sites More sharing options...
usmc1094 Posted August 19, 2013 Share Posted August 19, 2013 I think I'm going to try and polish the chamber with a dremel this week and take it to work to see how it runs. Link to comment Share on other sites More sharing options...
toothandnail Posted August 20, 2013 Share Posted August 20, 2013 Winchester bulk pak ? , we've had that same problem for quite some time, does the same in my Benelli , 930, MKA 1919, never had a lockup that bad, but routinely they would come out WITHOUT most the lip for the extractor to grab, Yes the SWELLED that much, or the "brass" was split. Quit buying Winchester about a year ago, Win AA's NO problems Thats good to know I forgot, my daughters boy friend's 870, DID lockup quite similar to what your describing, after the 3-4 time doing the butt stroke to the ground to clear it, he quit shooting it and switched to one of our MKA's Link to comment Share on other sites More sharing options...
compshootfl Posted August 20, 2013 Share Posted August 20, 2013 Federal bulk pack shoots ok in my experience also....run from the Winchester bulk packs, they are unreliable. Winchester AA run great. Shot my 2nd match with the 930 JM yesterday and it only made it through 1 of 4 stages. I was haveing failure to ejects that were bad enough to lock the gun up so tight that the range gunsmith had to take it to clear it before we could move on, and that was on the 1st stage. I'm going to blame the Wal-Mart bulk ammo. The smith said it looked like the cases had over expanded, jamming them in the chamber. Makes for a very long day. Ive ran about 600 rounds through mine now with Wallmart bulk packs. I shoot Federal though and have not had any cycling issues. I did have a round not fire yesterday on one of the 3GN classifiers, cycled the bolt by hand, kicked out the shell and I inspected it after the stage. It did not have any striker mark on it at all. This is the first time this has happened to me. Ill be placing an order this week for the 10/22 extra power spring and hope it gets here before the shotgun match this Sunday. Link to comment Share on other sites More sharing options...
rangerguy Posted August 20, 2013 Share Posted August 20, 2013 Asked Jerry himself and he and Lena run only Remington Gun club in there's. I have only run Ferderal bulk pack or Remington gun club both run great. Had a couple light strikes but replaced the hammer spring with a 10/22 and have not had a problem since. Link to comment Share on other sites More sharing options...
Solvability Posted August 20, 2013 Author Share Posted August 20, 2013 The polish seems to work - ran two boxes of the cheap crap Walmart Winchester through it without a hitch - the gun makes a nice snick snick sound loading that it did not in the past. I guess this means something else will break now. Link to comment Share on other sites More sharing options...
Thecelt Posted August 20, 2013 Share Posted August 20, 2013 i would have liked to have kept my 930 just to see if it would have been one of the good ones or a lemon (i tend to think it was a good one), but with only being able to afford one sasg for now i had to let it go. but i really think with the 10/22 hammer spring, and a little polishing on the 930 that its a gem of a gas operated sasg for the money. Link to comment Share on other sites More sharing options...
usmc1094 Posted August 20, 2013 Share Posted August 20, 2013 The polish seems to work - ran two boxes of the cheap crap Walmart Winchester through it without a hitch - the gun makes a nice snick snick sound loading that it did not in the past. I guess this means something else will break now. Thats good to know! Thanks for the info. Link to comment Share on other sites More sharing options...
LikesToShoot Posted August 20, 2013 Share Posted August 20, 2013 Shot my 2nd match with the 930 JM yesterday and it only made it through 1 of 4 stages. I was haveing failure to ejects that were bad enough to lock the gun up so tight that the range gunsmith had to take it to clear it before we could move on, and that was on the 1st stage. I'm going to blame the Wal-Mart bulk ammo. The smith said it looked like the cases had over expanded, jamming them in the chamber. Makes for a very long day. Ive ran about 600 rounds through mine now with Wallmart bulk packs. I shoot Federal though and have not had any cycling issues. I did have a round not fire yesterday on one of the 3GN classifiers, cycled the bolt by hand, kicked out the shell and I inspected it after the stage. It did not have any striker mark on it at all. This is the first time this has happened to me. Ill be placing an order this week for the 10/22 extra power spring and hope it gets here before the shotgun match this Sunday. Without a strike mark I'd look elsewhere for your guns' issue. Dirty piston, rings, tube, piston bore, bolt or anything that would keep it from going into battery. All my failures had a light strike and they fired with a second strike, no matter what ammo it was. No problems since the 10/22 spring.: Link to comment Share on other sites More sharing options...
Solvability Posted August 21, 2013 Author Share Posted August 21, 2013 I stopped by my gunsmith's shop today to report what I had done and found out - he also shot a 930 in the same 3 gun last Saturday and darned if he did not have the same failure to fire due to out of battery - he is going to try what I did - we both agreed the Mossberg would be a 700 dollar gun if they spent 25.00 more per gun on polishing and checking - the design is sound the execution is slap dash. I wish they would listen. Link to comment Share on other sites More sharing options...
Nickoli Posted August 21, 2013 Share Posted August 21, 2013 Without a strike mark I'd look elsewhere for your guns' issue. Dirty piston, rings, tube, piston bore, bolt or anything that would keep it from going into battery. All my failures had a light strike and they fired with a second strike, no matter what ammo it was. No problems since the 10/22 spring.: I can say that everything was clean, I fired 8 slugs before the match to see POI at 50 yards and had just cleaned it before that. I'm not sure what the problem was. I still need to look through it before this weekend, might even start to polish more stuff on it and see if it helps. Going to order the spring anyways since I need some twin loaders anyways. Link to comment Share on other sites More sharing options...
dickwholliday Posted August 23, 2013 Share Posted August 23, 2013 when my 930 was new i had the light strike issue but cleaning the rings seemed to have cured that problem.....mine has been shot a bunch.....recently however it seemed like every outing i'd have some sort of malfunction...... i really didn't take time to analyze it, but a couple of times it seemed like it did't cock the hammer because when id pull the trigger for the second shot it felt like the hammer had already fallen or just didn't cock for whatever reason....not sure if that was what had happed or not....if it ever happens again you can bet i'll stop and figure it out..... another of the malfunctions was a light strike...it had marked the primer...i reloaded the shell and it fired..... i replaced the hammer spring with the extra power Ruger one from Wolf and all the malfunctions seem to be gone....you can tell from the sound that it is obviously dropping the hammer with a lot more force....because this past weekend i shot it 75 times and the only thing out of the ordinary was that it failed to lock back after the last shot onone occasion....D I C K Link to comment Share on other sites More sharing options...
Solvability Posted August 26, 2013 Author Share Posted August 26, 2013 I am feeling more confident - I have competed in two 3 gun matches with good shotgun stages and no problems at all. It does make me think the problems are fixable if you are persistent - time will tell. Link to comment Share on other sites More sharing options...
Thecelt Posted August 26, 2013 Share Posted August 26, 2013 (edited) i think its well worth the effort to polish the chamber, shell stop, extractor and extractor plunger, the extractor groove on the barrel, the seam where the extension meets the factory mag tube, and the gas piston housing, all with a medium cratex wheel on a dremel. then hit the gas piston spring ends with a dremel so they dont scratch and drag on the mag tube. these few simple things will greatly improve the function of the 930 because that seems to be where mossberg cut corners to produce an affordable semi auto. throw in a 10/22 ep hammer spring and i think this will be as reliable as a this design will allow it to be. Edited August 26, 2013 by Thecelt Link to comment Share on other sites More sharing options...
usmc1094 Posted August 26, 2013 Share Posted August 26, 2013 I polished my chamber this week, and just got back from the range. No malfunctions out of 75 rounds as fast as I could load them. Hulls were all in a small pile about 4.5-5 feet away. All is looking good for now. Link to comment Share on other sites More sharing options...
Thecelt Posted August 26, 2013 Share Posted August 26, 2013 Polish up the other parts I mentioned along with just breaking the sharp corners on the shell stop as per the tutorial on brownells. You could go further to polish the bolt carrier and rails in the receiver along with the recoil spring. Use 00 steel wool on the spring. Link to comment Share on other sites More sharing options...
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