What has happened to the Mossberg 930?

[AustinT]

I don't mean to be a downer, but I think all the expert opinions say get a Benelli

[BobS761]

^^^This^^^. My JM Pro has taken a dump in two consecutive matches. I'm done.

[Thecelt]

Everyone says get a benelli or vm but not everyone has that kind of money, and for people who are not top competitors it can be tough to justify that cost. So many want to try the sport on a casual level and on a budget. It seems that the 930 is hit or miss with some running great and others puking so it stands to reason that the design is decent but perhaps quality control is lacking and some proper "tuning that all 930s should run respectably. I would expect as good as a benelli or vm due to design but they should be able to be reliable overall. I personally am thinking of selling my jm for an m2 but not because I am not happy with the jm but because the m2 is so darn nice. Heck I'd like to keep the jm buy an m2 this year and add a vm next year just to have all 3 but that's a bit unreaslistic from a $ point of view for me.

[AustinT]

You should not expect a JM to run better than a Benelli. Companies don't set prices in a vacuum. The Benelli costs more because it costs more to produce.

But:

A used Benelli is very affordable. Used Benellis are not like used Mossbergs. Used Benellis will continue to last far past the average and un-average shooter's needs. I have two and the most I've paid was $725. What does a new JM cost?

There's no reason to have all 3. If you're unhappy with the JM, pick a VM or Benelli and learn to use it. There is not nearly enough performance difference between the two to get heartburn about. People get all wound up about gear, once you have good gear it doesn't matter. The difference in being able to use your good gear is far greater than the difference between the equipment.

[Thecelt]

I would never expect a jm to surpass a m2 or vm (and I'd like to have all three just because I love firearms not because I need all three). I'd be happy if the jm provided 85% of the reliability of those guns considering it costs about half of an m2. In hindsight I do wish I waited and saved a bit more and got the m2 up front regardless of being happy with the jm. I don't shoot organized competition but I have my own "3 gun" style course that I practice on and I love shooting clays (I love shooting all disciplines for that matter).

[AustinT]

There's your answer, then. Quit worrying about which is better and enjoy your gun!

[Akkid17]

Cost + reliability = nova, I've seen several shooters do better than 50% or more of the tac field with one. 400 for the gun and 75 for a tube and hollow out the loading port if you want, a jm can't compete with than price or reliability.

[cajunautoxer]

I have not put that many rounds thru mine yet maybe 700ish. I did have a failure last match but took my 930 and shot sporting clays today. I just lubed the hell out of bolt. I have yet to clean the Pro and it ran fine today. I even used the cheap Wally World 100 pack

[Thecelt]

Cost + reliability = nova, I've seen several shooters do better than 50% or more of the tac field with one. 400 for the gun and 75 for a tube and hollow out the loading port if you want, a jm can't compete with than price or reliability.

i have a couple of mossy 500's if i wanted to use a pump. i like the sasg over the pump, but i just want the 930 to be the best it can be.

[ben b.]

Mine is awesome. I have (I think) had one feed jam last year in perhaps 700-800 rds, all were factory, mostly Estate 7.5s, but about 100 slugs and 30-40 were 00 Buck. I only remember the one jam last year which was on a stage and I cleared by racking the bolt and continuing. A buddy who borrows it on occasion and shoots reloads has had a few jams with his birdshot reloads.

Mine is a Waterfowl 930, to which I added the 24" unported barrel.

I am wondering if Mossberg rushed the JMs on the market, and cut the QC for this.

[Griz]

Its seems to me that there are 3 main issues people have with the 930 series guns.

http://www.brianenos.com/forums/index.php?showtopic=178449

Light primer strikes - fixed with 10/22 hammer spring

I think this "fix" adresses the sympton and not the real cause in most cases. Every light strike I have observed was most likely a failure to go into battery. I think that is the case because I always ask the shooter when he last took the rings off the piston and the answer is usually a blank look.

I have also see one where the guy did clean the piston but then put whatever wonder lube he believed in on the piston which gave him about 50% light strikes...

[Thecelt]

Griz, good points. Most seem to recommend cleaning the piston/rings about every 250 or so but many have gone longer. Once I get through breakin I plan to run a test of how I can run it without cleaning (but keeping the bolt lubed). Someone posted about running 75% gear oil and 25% syn trans fluid and he gets zero carnon buildup that needs to be scraped...

But help me understand how a dirty piston system keeps it from going into battery.

[cajunautoxer]

My SPX I'd clean around every 1k rounds and the Pro is close to that. I just used a good bit of M-Pro 7 lube

[LikesToShoot]

I cleaned and polished the tube. Scraped every particle out of the pistol bore. Polished the bore with steel wool on a brush. New firing pin. Replaced the piston return spring, recoil spring and installed a new piston. This new piston with ring and seal was cleaned with Brownells friction defense and wiped dry. Of course the bolt has been taken apart, cleaned and lubed with FD also.

When I bought this new it ran like the energizer bunny. USed to be able to run several hundred rounds through it without skipping a beat.

I'll be at the range again Friday to run some more rounds through it.

[lc2hl]

I use the 75/25 mix. I also clean quite often. If you run 2,3 or 400 rounds with enough, but not excessive lube, the carbon will not build up, and is easy to clean well. Look at it like this; If I leave dirty lube in place, heat and carbon cook it off and carbon builds up making a carbon paste (scoring also becomes an issue) the next time it is used. If I do not have enough lube in place, the carbon bakes onto areas where it does affect performance. Next use: Damage is quite possible.

Both scenarios=bad. Under gas piston rings= super bad.

Find the routine that YOUR gun requires, and stick to it. It does not matter what or who's gun it is. For the record, I have a M2 as well, but have not used it in comp, and probably never will as it is a 20Ga. The maintenance required for the M2 varies greatly from the 930's, and should be approached as such. Every gun has its own quirks, and if you are going to run it in comp, you need to know every one of them if you expect to have no malfunctions caused by the gun. Ammo and shooter induced issues; well you are on your own there.

[def90]

I picked a 24 inch JMPro 930 in late May/early June for the regular retail price. I have put about 400 rounds through it shooting clays so far without any issues. I like it, the only complaint out of the box was that the seam on the back of the stock was sharp and dug into my face as well as the checkering on the rear grip was sharp enough to give me a blister the first day I had it out. I took care of both issues pretty easily.

[Nuke8401]

+1 Griz, My money is also on dirty piston/rings.

But help me understand how a dirty piston system keeps it from going into battery.

Why a dirty piston/rings keeps the gun from going into full battery. (I could be wrong)

What I think is happening is that the buffer spring is the main force moving the bolt forward/loading the next shell in the chamber. The spring on the mag tube returns the piston to the full forward position. I'm not sure if the design relies on any force from the recoil buffer to move the piston forward but it seems when there is resistance/dirt on the piston and rings that extra friction causes the bolt to stop short of full battery. The piston transmits force to the bolt via the plastic sleeve on the mag tube and the double rod assembly and this also transmits force in the other direction as the bolt moves forward. I think when the piston moves too slowly or stops short the bolt does not go firmly into battery.

When cleaning and assembling my gun I make sure the piston returns to the fully forward position with just the force of the spring on the mag tube. When reassembling leave the forend off and just hold the barrel in place, grab the piston and slide it to the rear and let go. It should snap forward into the piston bore. On my gun, I can induce extra friction when assembling the forend and screwing on the mag tube if I allow the assembly to twist. You can do this with e forend off, twist the barrel and you will see the extra friction slows/stop the piston from going fully forward.

When you think you have the piston clean, take a steel scribe/pick and try scraping the inside of the piston rings (groves) and the groves on the outside. These areas are hard to clean even with a wire wheel on a dremel. They are not seating surfaces so even if you did manage to scratch them it would not impact the function only make it harder to clean in the future. Most of the times I clean my piston/ring with a wire wheel on a dremel and check afterwards with a scribe I find more dirt/carbon as it hides from being polished by the wire wheel.

Check with a scribe, you might be surprised, I was.

Edited August 1, 2013 by Nuke8401

[Thecelt]

ok, i get it now. if the piston cant seat itself all the way home so to speak, the entire assembly can interfere with the bolt going into battery... i appreciate the explanation. the stronger hammer spring certainly wouldnt address the problem, but could help overcome the issue keeping the gun running more reliably even when dirty. i think its a worthwhile change.

Edited August 1, 2013 by Thecelt

[LikesToShoot]

ok, i get it now. if the piston cant seat itself all the way home so to speak, the entire assembly can interfere with the bolt going into battery... i appreciate the explanation. the stronger hammer spring certainly wouldnt address the problem, but could help overcome the issue keeping the gun running more reliably even when dirty. i think its a worthwhile change.

I had already ran through the piston, rings, return (recoil) spring and other items already mentioned and continued to have problems up to last Sunday. This week I installed the 10/22 spring, without cleaning ANYTHING on the gun. Today I ran three more problem free boxes (two Fed. and one my reloads) through it for a total of around 135 with ZERO issues with the new hammer spring.( On 7/30/13, I shot 60 rounds w/new spring, Message #18 http://www.brianenos.com/forums/index.php?showtopic=178449 )

Next week I'll burn a couple more boxes then strip it down for a good cleaning before next weekends local G3G match.

If your guns not having a problem I wouldn't replace a thing. As mentioned clean all the above items very well and maybe have a HD 10/22 spring ready to go if needed. I chased the sticking piston, not going into battery angle as far as I could go, (new piston, rings, springs) but mine still had issues. As of right now my JM 930 is running as good as when I first got it.

Edited August 3, 2013 by LikesToShoot

[Thecelt]

That's awesome news. I'm hoping I can get out and run a 100 rounds through mine tomorrow to finish breakin and see how much smoother she's gonna run with polished chamber, and shell stop. I actually put mine up for sale, not because I'm not happy with the jm but because I can't get that damn m2 out of my head! I'd like to keep both but its not in the budget right now.

[bani]

i have a mossberg 930 and a remington 1100 trap, both of which always go to the trap range with me.

the mossberg is the only one which keeps running reliably -- about 20k rounds through it now with few issues. wooden forend cracked and then blew up in the middle of a trap round. well, thats why i keep the remington as a backup gun. replaced the furniture with plastic. now its ugly tupperware but at least i won't worry about scratching it!

the remington sure looks pretty, even when it malfunctions -- which is often.

mossberg parts can be a pain to come by, but it can be done.

[gondo]

Everyone says get a benelli or vm but not everyone has that kind of money, and for people who are not top competitors it can be tough to justify that cost. So many want to try the sport on a casual level and on a budget. It seems that the 930 is hit or miss with some running great and others puking so it stands to reason that the design is decent but perhaps quality control is lacking and some proper "tuning that all 930s should run respectably. I would expect as good as a benelli or vm due to design but they should be able to be reliable overall. I personally am thinking of selling my jm for an m2 but not because I am not happy with the jm but because the m2 is so darn nice. Heck I'd like to keep the jm buy an m2 this year and add a vm next year just to have all 3 but that's a bit unreaslistic from a $ point of view for me.

Buy once cry once all that gunsmith work keeping a 930 running could end up costing you more then the m2. Plus let's face it any that can come up with enough for a 930 or three gun in General can skip a few matches a save the ammo money to upgrade to an m2 or however you want to justify it right?

[sperman]

The Stoeger M3000/M3500 seems to be the budget shotgun of choice these days.

[gondo]

The Stoeger M3000/M3500 seems to be the budget shotgun of choice these days.

Hey that's a great point I would definitely pick one of those up if things were real tight

[rtp]

Everyone says get a benelli or vm but not everyone has that kind of money, and for people who are not top competitors it can be tough to justify that cost. So many want to try the sport on a casual level and on a budget. It seems that the 930 is hit or miss with some running great and others puking so it stands to reason that the design is decent but perhaps quality control is lacking and some proper "tuning that all 930s should run respectably. I would expect as good as a benelli or vm due to design but they should be able to be reliable overall. I personally am thinking of selling my jm for an m2 but not because I am not happy with the jm but because the m2 is so darn nice. Heck I'd like to keep the jm buy an m2 this year and add a vm next year just to have all 3 but that's a bit unreaslistic from a $ point of view for me.

Buy once cry once all that gunsmith work keeping a 930 running could end up costing you more then the m2. Plus let's face it any that can come up with enough for a 930 or three gun in General can skip a few matches a save the ammo money to upgrade to an m2 or however you want to justify it right?

Lol, funny math you have there. There aren't many issues the JM requires paid gunsmithing on, and I'd hate to ask what you pay for shotgun shells that a few matches worth of shotgun shells makes up the difference in price between the JM and an M2?