930 jm pro

[Dberm118]

I've wanted this gun for quite some time. I'm jumping from a slightly built 870. I'll be gaining 2 rounds of capacity as the jm i pick up in 10 days is a 9+1 my 870 a 7+1. 

 

Anywho it seems the later jm pros have had the minor upgrades tha caused most of the issues in 2014 for the gun even though they haven't released a 'generation 2' so to speak. 

 

My question is what do you guys feel is necessary for this thing to run flawless. My first plans as I load deuces is to do some port work. Aside from that I was looking at or3guns MST and follower for reliability purposes. 

 

Any other recommendations.. thanks to CA I can't bust her out of jail for 10 days which I have a match that Sunday. Wondering if I should just run her without trying her out or run my 870 one last time.

Edited August 22, 2016 by Dberm118

[SteveA]

My experience has been with a 930 waterfowl - Polish the shell stop so it reliably releases sells onto the lifter & swap out the hammer spring for a Wolff 10/22 extra power, to prevent light strikes.

[Solvability]

1 hour ago, SteveA said:

My experience has been with a 930 waterfowl - Polish the shell stop so it reliably releases sells onto the lifter & swap out the hammer spring for a Wolff 10/22 extra power, to prevent light strikes.

 

good start - I had to go through mine and polish most every action part as well as the spring change. It may never be as reliable as a Benelli but it will equal or surpass an 1100

[mpom]

Sight it in with shot shells and slugs. Older ones such as mine shot very high, corrected with higher front fiber optic triangle.

[swordfish]

Never had any problems with mine but I put all the parts in as soon as I bought it. Definitely polish the shell catch. Also make sure you're good on a maintenance schedule, the thing blows gunk everywhere and needs cleaning after a couple hundred rounds.

Ran 100 rounds of the hottest magnums I could find, then cleaned and swapped parts to the OR3Gun setup. 10/22 hammer spring (although I never had any problems before, but hey why not). Monk Cut for the loading port. Dovetailed an XS rifle sight into the rib. Shortened the recoil spring tube an inch and then took an inch off the stock and put a Kick-eez pad. Hasn't let me down yet, and I run the ultralight Top Gun stuff from Federal, plus Fiocchi low recoil slugs. Cleaning is a bitch though.

[Dberm118]

Well I'm pretty excited I get to pick it up tomorrow!!!

I will be shooting groups with shotshell and slugs to see how she shoots than loading port work once I find out exactly where I want it. Match on sunday don't know If I will just wing it and try to shoot her there or hold off until I know how well she shoots. matchsaver on the way and have some Or3gun stuff in a cart ready to order!!

[Dad]

My son shoots 1 and has had zero issues, we just installed a welded lifter from C-Rums

he cant wait to try it out Monday.

 

[Dberm118]

So I picked her up and I must say i'm absolutely blown away! This gun is an absolute monster! ran 1200fps fiocchi and Winchester ammo along with Winchester 1600fps slugs and it is amazing. The trigger on it is unbelievable for a gun in it's price range.

All I did was strip it clean it and oil it all. Slightly polished the bolt and deburred any sharp edges. I pulled the recoil spring and plunger and deburred the spring so it doesn't destroy the stock recoil system. I did also pull the barrel clamp off.

I could not be happier with this purchase and hope it keeps rocking!!

 

Edited September 5, 2016 by Dberm118

[Pistolpete9]

Just ran mine at the range today and it was a champ the whole time.  Third trip out and haven't had a bobble yet.  Did a crappy home job on the loading port and it worked just fine

[uewpew]

6 hours ago, Dberm118 said:

So I picked her up and I must say i'm absolutely blown away! This gun is an absolute monster! ran 1200fps fiocchi and Winchester ammo along with Winchester 1600fps slugs and it is amazing. The trigger on it is unbelievable for a gun in it's price range.

All I did was strip it clean it and oil it all. Slightly polished the bolt and deburred any sharp edges. I pulled the recoil spring and plunger and deburred the spring so it doesn't destroy the stock recoil system. I did also pull the barrel clamp off.

I could not be happier with this purchase and hope it keeps rocking!!

 

Cleaning/deburring the parts is a good start.  I did this with mine and it's ate everything I've fed it with no issues.  Keep the operating system clean and you'll be happy with your purchase!  In case you haven't found it yet, Jerry has a great 23min video on cleaning the 930.  just Google "Jerry Miculek 930 cleaning"  

[Dberm118]

14 hours ago, uewpew said:

Cleaning/deburring the parts is a good start.  I did this with mine and it's ate everything I've fed it with no issues.  Keep the operating system clean and you'll be happy with your purchase!  In case you haven't found it yet, Jerry has a great 23min video on cleaning the 930.  just Google "Jerry Miculek 930 cleaning"  

I've watched it awesome video.. the bolt seemed a little rough and the coating wasn't very smooth so I took some scotch bright to smooth it out then just hit it with a polishing wheel to make it smooth. that helped the action quite a bit. Or it could've been the simple fact I stripped it and lubed it properly haha.

 

Anywho! I'm happy and will be doing the maintenance to keep it in good form.

[Dberm118]

So I'm still loving this gun. I will be dropping down to see if she will cycle 1175's or 1150's.

She cycles 1200fps shells no problemo. I received my Or3gun follower and forearm retainer it really brings the forearm closer to the receiver a significant amount.

I did some very minor port opening and will hit it a little harder when I get more range time and get it more dialed to where I want more opening.

 

As far as lifter, does anybody know the material?? I can fab and have run CNC machines for 6 years however I do not want to machine one I just want to weld this one up and I will probably mill it smooth than sand or file it.

 

Thanks guys!

[Cuz]

Glad you're enjoying your new shotgun.  It's always fun to hear about someone getting a new toy and loving it!!!

[Pistolpete9]

Just an update to my earlier comments for posterity sake.  My JM Pro doesn't like the first round getting loaded into the tube with the low recoil slugs from Fiocchi.  They have a pretty prominent rim at the front that catches the stock follower at a weird angle and causes it to need some extra oomph to get it in.  After that it's not problem at all.

Furthermore, I had me first issue.  It wasn't Mossberg's fault though.  It was Winchester's.  I had a very strange load.  It was out of round I think and so it made it into the chamber and even fired, but it didn't come out.  Not for lack of trying on the extractor's part.  The rim was ripped off on the portion that the extractor touched.  I was able to eventually work the shell out and the gun ran great with everything for the rest of the day, but wanted to make sure I told it like it happened.  In a competition, I would have been done for the day.

[HawkMoney]

I shot a jm pro for a year in 3 gun. I had a lot of problems with it and so did a lot of my friends that had them also. If i didnt clean it every 100 rounds it would start having problems especially with lighter loads. Cleaning it was always a real hassle with the gas system under the hand guard. It shot slugs way off of poa so i sold it and bought a benelli m2 and that was the best decision i ever made. The inertia system is so reliable with every load i put in it and i have still yet to clean the thing after about 1500 rds. It also shoots low recoil slugs poa. A cheaper option would be a stoeger. Basically a copy of an m2 for half the price. 

[kpbaer]

My JM has run everything I put I it for 4 years. This year it started to fire one round then a light hit on the 2nd shot. I finally figured  it out. The bolt wasn't closing all the way. Do to my lack of cleaning. You must take off the rings on the piston. If the piston does not slide easily your have problems. I love when 1500.00 shot guns jamb and my 500.00 dollar gun runs great.

 

 

[HawkMoney]

I used to get a kick out of that to when I shot a m&p and a jm pro until I realized I was the one having all the problems... Don't get me wrong.. If you love cleaning your gun more than shooting it the jm pro is great.

[racknrider]

6 hours ago, Pistolpete9 said:

 

Furthermore, I had me first issue.  It wasn't Mossberg's fault though.  It was Winchester's.  I had a very strange load.  It was out of round I think and so it made it into the chamber and even fired, but it didn't come out.  Not for lack of trying on the extractor's part.  The rim was ripped off on the portion that the extractor touched.  I was able to eventually work the shell out and the gun ran great with everything for the rest of the day, but wanted to make sure I told it like it happened.  In a competition, I would have been done for the day.

I've had the same issue with the bulk pack Winchester stuff. I will not buy it again. The Federal bulk stuff has been ok. 

Got tired of cleaning my 930 all the time and got an M2. 

[Dberm118]

14 hours ago, kpbaer said:

My JM has run everything I put I it for 4 years. This year it started to fire one round then a light hit on the 2nd shot. I finally figured  it out. The bolt wasn't closing all the way. Do to my lack of cleaning. You must take off the rings on the piston. If the piston does not slide easily your have problems. I love when 1500.00 shot guns jamb and my 500.00 dollar gun runs great.

 

 

must agree. I've put several rounds through my JM pro and have cleaned it twice since I bought it.  She runs like a top. well worth the money in my opinion though it seems that since I bought mine brand new recently Mossberg has taken some steps to remedy a majority of the problems the first 930 pros had.

 

Anywho, great gun for the money and I'm loving mine.

[Pistolpete9]

Yeah, I have 400 assorted rounds uncleaned at this point and I'm going to try and see how many more it will take before I have to clean.  Seems to be running pretty well.  Mine also shoots pretty accurately with slugs.  I guess the earlier ones had more problems.  I had an inertia gun (M3000) and definitely prefer the 930, which surprises me.  Not saying that inertia guns aren't good guns, but the 930 seems to be just fine for me.

[HawkMoney]

Thats great that you guys are having good luck with yours. Seems like i had an older one. Its nice to see that Mossberg has fixed the problems. keep us posted on how long you can go without cleaning before running into problems. A friend of mine is trying to decide between a jm pro and a stoeger m3k.

[Pistolpete9]

Can't say either are bad guns.  I liked my M3000, but wasn't crazy about the lack of accessories or different barrel options. I can throw a different spring, cap and barrel on my JM pro and go hunting, or throw on an 18 inch barrel and have a great HD gun.  Hard to do with a M3000.  I also thought that the cycling characteristics were much more varied by the load (normal for an inertia gun).  I may end up going back to an inertia gun, but the Benelli system is far superior IMO.  Worth the extra dollars.

[Rob72]

I'm not a competitive shooter, and rarely post.  Having said that, I shoot a fair bit recreationally and enjoy some smithing.  In the 90's I owned an M1, M2 and finally an M3.  Benelli was my introduction to semi-shotguns.  Life happens and they were sold off.  Several years later, my replacement was the Stoeger M2000; just last year, I decided to try gas guns for the the first time, and picked up a stamped SPX and another labeled (but not stamped) SPX.

The unstamped gun did not have quite the fit of the stamped gun; looser trigger guard, less contact with the rear shell stop and the trigger guard, few other points.  Before shooting I did the same thing I've done with Benellis and the M2000:

1) complete disassemble

2) Remove/polish all burrs and wear marks on bolt group, trigger group and magazine parts (including spring tails)

3) Chamfer mag tube mouth and throat; chamfer action spring tube throat

4) Polish action spring tube with 300 grit pad (3M green) using light oil, running the rod with a hand drill

5) Polish inside of mag tube with a brake hone, then down to 600 grit. 

6) Polish outside of mag tube down to 1500 grit

7)  Lube with moly-dry lube throughout most of the gun.  Light moly grease on the bolt and bolt/receiver rail engagement.  Lightly swab gas system with penetrating oil and leave in place.

Upgrade parts: JM chromed pistons, 9300 Jungle Gun stainless mag tubes, OR3Gun Field kit, Hahn Precision extended rail/safety.

First outing, with myself and 2 other shooters, with the SPX stamped gun: 525 rounds of Suprema #7 1/2 and another 250 of mixed Rem and Winchester 2 3/4 and 3" 00 and slugs.  Flawless. Gun #2(300 rnds of Suprema) had an issue only because I didn't seat the shell latch retaining pin spring.

Edited November 9, 2016 by Rob72
addition

[Pistolpete9]

Update:. The 435 rounds without a cleaning proved to be the stopping point this time.  Fire, fail, fire, fail.  Not fully closing or not being struck hard enough.  Take your pick.  I'll clean it well and probably do the 10/22 spring as well.  Not sure if any of the or3gun parts would have prevented this.

[Rob72]

On 11/20/2016 at 8:17 PM, Pistolpete9 said:

Update:. The 435 rounds without a cleaning proved to be the stopping point this time.  Fire, fail, fire, fail.  Not fully closing or not being struck hard enough.  Take your pick.  I'll clean it well and probably do the 10/22 spring as well.  Not sure if any of the or3gun parts would have prevented this.

Just my suggestion- I'd spend the $45 for the ported spacer tube.  The action has MUCH less drag than with the stock parts, as the carbon/gunk that like to accumulate on the tube get blown out.