Mossberg 930 JM
- Thread starter dean1818
- Start date
most people report slugs to shoot about 6" high and to the right (iirc) on the jm at 50 yards. i just ordered some slugs yesterday so i will have to see.
as for reliability, i hear from the majority of people that they are very reliable, but... i have heard of more complaints about them on different forums than some other (more expensive) sasg's. but you know how it goes with posting complaints on forums, you will always hear more complaints on a forum than praises. i dont have enough rounds through mine to effectively comment from personal experience, but so far so good.
as for reliability, i hear from the majority of people that they are very reliable, but... i have heard of more complaints about them on different forums than some other (more expensive) sasg's. but you know how it goes with posting complaints on forums, you will always hear more complaints on a forum than praises. i dont have enough rounds through mine to effectively comment from personal experience, but so far so good.
allaroundhunter
New member
I like my 930 JM Pro (don't love it). I bought it back in October for 3 gun and it has been pretty good. As far as slugs go? It shoots them into about 3" groups about 2" high-left of the target at 50 yards (which is where most smoothbore shotguns shoot slugs).
Now, for the bad:
1. When I purchased the gun I discovered that the magazine tube where the extension connected was dented. Not just a little dented, but to the point that the follower could not make it past. The gun was essentially a 4+1 gun instead of 9+1.
2. After ironing out that problem, I discovered that the stock follower was a piece of junk.... I scrapped it for a GG&G follower which has worked well since.
3. There is a piece in the bolt carrier that you really should stake. Before I did it would get loose and rattle, and really made reassembly a pain in the butt.
All in all, it took me about 2-2.5 months to get the gun to run reliably, but since then I haven't had a problem.
A little good news to finish it off:
Even though the gun is now "used", I can still make a decent profit if I wanted to sell it
*I have about 85 slugs, 30 buckshot, and 1200 birdshot rounds through my gun as of now.
Now, for the bad:
1. When I purchased the gun I discovered that the magazine tube where the extension connected was dented. Not just a little dented, but to the point that the follower could not make it past. The gun was essentially a 4+1 gun instead of 9+1.
2. After ironing out that problem, I discovered that the stock follower was a piece of junk.... I scrapped it for a GG&G follower which has worked well since.
3. There is a piece in the bolt carrier that you really should stake. Before I did it would get loose and rattle, and really made reassembly a pain in the butt.
All in all, it took me about 2-2.5 months to get the gun to run reliably, but since then I haven't had a problem.
A little good news to finish it off:
Even though the gun is now "used", I can still make a decent profit if I wanted to sell it
*I have about 85 slugs, 30 buckshot, and 1200 birdshot rounds through my gun as of now.
allarounder, good point about the follower. i just found out that when i try to fee Rio Royal ammo into the tube the first round gets hung up on the follower. the rolled lip is long and deep on the end of Rio's ammo and due to the taper on the stock follower the lip of the shell gets wedged up there and makes the round very hard to force in. the second round is no problem because the lip isnt getting hung up on the follower. i plan to change out followers and i was just looking at the gg&g. have you ever run rio ammo, or have you had any other issues with that follower?
also, what else did you do to increase reliability. i recently picked mine up (ordered it ages ago but too forever to come in) so i dont have much more than 100 rounds down range and so far so good, but if there is anything simple I can do to help increase reliability id like to.
also, what else did you do to increase reliability. i recently picked mine up (ordered it ages ago but too forever to come in) so i dont have much more than 100 rounds down range and so far so good, but if there is anything simple I can do to help increase reliability id like to.
allaroundhunter
New member
With the new follower it runs fine with Rio ammo. Only other modifications are that I had a gunsmith friend go through the action and smooth it up and clean it out.
And keep some CLP in the action.
And keep some CLP in the action.
allaroundhunter
New member
I did try Rio before, but I can't day whether it was causing the problems or the gun was (I would put my money on the gun).
When I reload I am typically throwing two shells in the gun at once so I'm usually pushing them in hard enough not to notice a little resistance or hang-up.
When I reload I am typically throwing two shells in the gun at once so I'm usually pushing them in hard enough not to notice a little resistance or hang-up.
allaroundhunter
New member
Glad to hear it's working for you!
I just picked up a 930 JM Pro to use for 3 gun and so far I like it.
I only have 50rds through it but it worked perfect out of the box even with the lightest loads.
The only thing I don't like is the cut out on the carrier, it grabbed my thumb a couple times so I'm sending it out to get welded up.
I only have 50rds through it but it worked perfect out of the box even with the lightest loads.
The only thing I don't like is the cut out on the carrier, it grabbed my thumb a couple times so I'm sending it out to get welded up.
Destructo6
New member
Mine is going back to Mossberg tomorrow.
It will consistently fail to release a shell from the magazine tube.
Upon close inspection and comparison with another 930 JM Pro, the "rear shell stop" has a small ridge left on it from manufacture, that should have been removed. Not sure if this ridge is THE culprit, but it's going back.
I have put about 350 rounds of various types and have rarely gotten through an entire tube of shells without such a failure.
It will consistently fail to release a shell from the magazine tube.
Upon close inspection and comparison with another 930 JM Pro, the "rear shell stop" has a small ridge left on it from manufacture, that should have been removed. Not sure if this ridge is THE culprit, but it's going back.
I have put about 350 rounds of various types and have rarely gotten through an entire tube of shells without such a failure.
That sucks man... keep us posted. I recently polished my chamber and the shell stop. I've considered polishing up the bolt carrier and rails inside the receiver as well as the recoil spring and recoil spring tube but I want to test out the gun first with chamber and shell stop polished. Not that my gun seems to be a problem gun (too early to tell really) but it can't hurt and can only help.
Check out this helpful link...
http://www.brownells.com/.aspx/lid=...The-Tube-Problem?source=CJ&ch=aff&AID=6147349
Check out this helpful link...
http://www.brownells.com/.aspx/lid=...The-Tube-Problem?source=CJ&ch=aff&AID=6147349
Destructo6
New member
Got it back from Mossberg just less than a week ago.
I disassembled it immediately and could not figure out what they had done to it, if anything. The only paperwork included in the box was a half sheet of paper that spoke of cleaning the gas piston.
I called Mossberg and they said that they'd replaced the gas piston as it was defective. I found this strange, since the gun had no problems extracting and ejecting spent shells.
The problem was, and remains, that a new shell is not always released from the magazine tube.
As I stated in my previous post, the rear shell stop had an odd ridge along the lower edge that is not present in 2 other 930s that I've inspected.
That "rear shell stop," to the best of my knowledge, was not touched while in Mossberg's posession.
I do no believe that the tech ever looked at the detailed description of the failure that Mossberg asks you include in the box with the returned shotgun.
It's slated to go back, again, but this time Mossberg is paying for it. However, I'll try to shoot a match before it goes.
I disassembled it immediately and could not figure out what they had done to it, if anything. The only paperwork included in the box was a half sheet of paper that spoke of cleaning the gas piston.
I called Mossberg and they said that they'd replaced the gas piston as it was defective. I found this strange, since the gun had no problems extracting and ejecting spent shells.
The problem was, and remains, that a new shell is not always released from the magazine tube.
As I stated in my previous post, the rear shell stop had an odd ridge along the lower edge that is not present in 2 other 930s that I've inspected.
That "rear shell stop," to the best of my knowledge, was not touched while in Mossberg's posession.
I do no believe that the tech ever looked at the detailed description of the failure that Mossberg asks you include in the box with the returned shotgun.
It's slated to go back, again, but this time Mossberg is paying for it. However, I'll try to shoot a match before it goes.
Destructo6
New member
Tried that a while ago and it made no difference.
When I removed the shell catch assembly to do this mod, I noticed a problem with the rear shell catch.
If you look at that shell catch on the Brownells site, the catch has a up/down groove towards the rear and parallel with the back edge. On mine, the lower portion of that groove terminates before it hits the bottom of the shell catch. It also has a small ridge along the bottom edge.
When I removed the shell catch assembly to do this mod, I noticed a problem with the rear shell catch.
If you look at that shell catch on the Brownells site, the catch has a up/down groove towards the rear and parallel with the back edge. On mine, the lower portion of that groove terminates before it hits the bottom of the shell catch. It also has a small ridge along the bottom edge.
Destructo6
New member
Received the 930 JM Pro back from Mossberg/Maverick Arms on Thursday. These are the things that were listed on the invoice:
The trigger group was also replaced, but not listed for some reason. It had some peening on the front of the casting.
The Shell Stop was definately bad, but I'm not quite sure why the other stuff had to be replaced. However, I'm not complaining.
I ran 30 full power slugs and 50 rounds of birdshot though it with 1 hitch. Slug #29 extracted and ejected, but slug #30 wasn't released from the mag tube. The remaining 30 rounds of birdshot cycled perfectly.
Finally, I'm Happy.
- Gas Piston Assembly 935/930
935 Pressure Ring
930 Pressure Spring (blue)
930 Shell Stop
The trigger group was also replaced, but not listed for some reason. It had some peening on the front of the casting.
The Shell Stop was definately bad, but I'm not quite sure why the other stuff had to be replaced. However, I'm not complaining.
I ran 30 full power slugs and 50 rounds of birdshot though it with 1 hitch. Slug #29 extracted and ejected, but slug #30 wasn't released from the mag tube. The remaining 30 rounds of birdshot cycled perfectly.
Finally, I'm Happy.