LHshooter Posted September 1, 2014 Share Posted September 1, 2014 Just participated in a local 3-Gun match yesterday, and once again had problems with my Mossberg 930 JM Pro. This time I had two instances of the fired shell failing to extract. The first time, the extractor pulled the brass head off the hull and left the hull in the chamber. I had to stick a rod down the barrel to push the hull out. This happened with a Remington Gun Club 1200 FPS shell. Then, after about 30 rounds another shell failed to extract a Winchester AA shell. This time, it was wedged so tight in the chamber I couldn't pull the bolt back. When I finally forced the bolt open, the extractor had bent back the rim of the brass head. The shell was still stuck in the chamber and I once again had to push a rod down the barrel to push the shell out. When I got home I took off the barrel but did find anything obvious. When I put an unfired shell in the chamber it slides in and out easily. When I put in the shell with the bent rim, it goes in tight and has to be pushed out. It seems that the hull has expanded. When I measure the fired hull with a pair of calipers, it is several thousandths wider than an unfired hull, enough to get it stuck in the chamber. Does anybody know what might be causing this problem? I have read about failure to extract issues withe JM Pro, but not with the shells being stuck in the chamber. I'm ready to throw this thing in the garbage. A year ago I had double feed problems and it took 3 months to get the gun back from Mossberg and it still does it every once in a while. Any help would be greatly appreciated. Thanks Link to comment Share on other sites More sharing options...
usmc1094 Posted September 1, 2014 Share Posted September 1, 2014 I had to use a dremel and some polishing compound on the chamber of my JM. It doesn't take long, but the smoother you make it the better it will work. It still happens with Winchester shells maybe 1 out of 100, but haven't had any trouble with gun club or federal bulk packs. Link to comment Share on other sites More sharing options...
usmc1094 Posted September 1, 2014 Share Posted September 1, 2014 This is a Winchester shell that had to be pushed out with a rod before I polished the chamber. Link to comment Share on other sites More sharing options...
LoganbillJ Posted September 1, 2014 Share Posted September 1, 2014 Winchester universal will stick in any gun. I have seen more guns go down at 3 gun matches due to universals than anything else. If AAs are sticking you may need to do a little polishing. Link to comment Share on other sites More sharing options...
LHshooter Posted September 1, 2014 Author Share Posted September 1, 2014 This is a Winchester shell that had to be pushed out with a rod before I polished the chamber. Hey usmc1094 - the shell in your photo looks just like mine. I was hesitant to use any compound in case I took off too much material and made things worse, but I guess I will try it a little at a time. With my stupid luck when I do something to the JM Pro and then shoot a box of shells I don't have a problem. Then, when I go to a match guess what - a problem! Thanks again, glad to hear I'm not the only guy, not that I wish gun problems on anyone. Link to comment Share on other sites More sharing options...
LHshooter Posted September 1, 2014 Author Share Posted September 1, 2014 I had to use a dremel and some polishing compound on the chamber of my JM. It doesn't take long, but the smoother you make it the better it will work. It still happens with Winchester shells maybe 1 out of 100, but haven't had any trouble with gun club or federal bulk packs. usmc1094 - sorry to bother you again, but when you used the Dremel, how far into the chamber did you polish? The length of a shell or just an inch or so? The other thing that bothers me is that I probably fired 300 or 400 rounds through the shotgun using the same shells as yesterday and it never had that problem, so what caused it now? I would think it would have happened sooner than after a few hundred rounds went through it. Link to comment Share on other sites More sharing options...
usmc1094 Posted September 1, 2014 Share Posted September 1, 2014 I went as far as I could go. I use one of these because the regular dremel is to fat. http://www.amazon.com/gp/aw/d/B0000302Y8?cache=ee9a2bf35dc81da2641f536cb2572ac7π=AC_SX110_SY165_QL70&qid=1409611452&sr=1-6#ref=mp_s_a_1_6 I use Nu Finish car polish. Link to comment Share on other sites More sharing options...
usmc1094 Posted September 1, 2014 Share Posted September 1, 2014 I had to use a dremel and some polishing compound on the chamber of my JM. It doesn't take long, but the smoother you make it the better it will work. It still happens with Winchester shells maybe 1 out of 100, but haven't had any trouble with gun club or federal bulk packs. usmc1094 - sorry to bother you again, but when you used the Dremel, how far into the chamber did you polish? The length of a shell or just an inch or so? The other thing that bothers me is that I probably fired 300 or 400 rounds through the shotgun using the same shells as yesterday and it never had that problem, so what caused it now? I would think it would have happened sooner than after a few hundred rounds went through it. Mine shot about 150-200 before anything went wrong. Since I've polished the chamber and added an RCI mag tube there has been zero problems. Probably close to 1000 rounds. I do clean it after every match, including taking the gas piston apart. I think I have only touched up the polishing once, normally if there is anything in the chamber it just wipes away. If you want I could probably try to take a picture of the chamber tonight. Link to comment Share on other sites More sharing options...
Mahlsan Posted September 2, 2014 Share Posted September 2, 2014 I had this happen as well the one time a match posted #8 shells only, don't have any.? Typically run 7.5. So I ran to Wally World and bought these same shells, same result with Winchester I only run AA from Winchester everything else runs fine. I tend to run mine wet though. Link to comment Share on other sites More sharing options...
LHshooter Posted September 2, 2014 Author Share Posted September 2, 2014 I had to use a dremel and some polishing compound on the chamber of my JM. It doesn't take long, but the smoother you make it the better it will work. It still happens with Winchester shells maybe 1 out of 100, but haven't had any trouble with gun club or federal bulk packs. If you want I could probably try to take a picture of the chamber tonight. No big rush, but if you think a photo will help and don't mind, post a photo. I have that flex shaft attachment for my Dremel so I'm good to go with that. I really appreciate your help with this. I feel vexed with this gun. As an aside, I always clean my gun thoroughly after use and follow Jerry Miculek's video that goes into great detail on how to really clean the complete gun. Thanks gain - Herb Link to comment Share on other sites More sharing options...
usmc1094 Posted September 2, 2014 Share Posted September 2, 2014 No problem! I got tired of people telling me my Mossberg was a big pile of poop. So with a little love I showed them how good it could work. I'll get that picture for you tomorrow after work. Link to comment Share on other sites More sharing options...
Nickoli Posted September 3, 2014 Share Posted September 3, 2014 (edited) If you want to throw it in the garbage, I'll send you my ffl info and you could just send it there. I have about 6 hours worth of work into mine. I polished the chamber and have yet to have this issue. Mine won't run Rio target loads. Everything else runs perfectly. Once the bugs are worked out it will be a good gun. I'll also add i am finally around 8000 shells through it now and only issues are with the Rio shells i tried. Edited September 3, 2014 by Nickoli Link to comment Share on other sites More sharing options...
Bam Bam Posted September 3, 2014 Share Posted September 3, 2014 I run only Winchester Target 7.5 1145FS load in mine, not an issue. Also have spent about 12hrs over 3 years tuning it, but runs fast and no issues except for operator errors. :-) BGC Link to comment Share on other sites More sharing options...
LHshooter Posted September 3, 2014 Author Share Posted September 3, 2014 I cleaned the hell out of the chamber using a brass brush, a Dremel, and then when I thought it was clean, wrapped patches around the brass brush for a tight fit and with polish on the patch, chucked it in a drill and removed even more black crud. Went to the range today and fired 15 rounds each of 3 different brand shells and had ZERO issues. I hope that solves my problem. I guess when cleaning I am really going to have to work on the chamber. Now I hope it doesn't hiccup during my next match. Thanks again for all the helpful replies. Link to comment Share on other sites More sharing options...
SteveA Posted September 5, 2014 Share Posted September 5, 2014 This is a Winchester shell that had to be pushed out with a rod before I polished the chamber. With that ammo, my 930 ripped the heads off from 3rds (I bought 1000rds and thought it was a good deal - I now know why it was cheap). Changed ammo and its been fine since. Link to comment Share on other sites More sharing options...
ojs643 Posted September 6, 2014 Share Posted September 6, 2014 Ive tried different brands in mine, when i had it. The best brand that gave me no issues was the federal (bulk- 7 1/2 & 8) from walmart. My JM didnt really like anything else. I now have a versamax- LIFE IS GOOD NOW!! Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now