I’ve been happily shooting my JM Pro for monthly outlaw and 3GN matches since April 2012, @ ~2,500 rounds.  Once I added the Nordic shell follower I have been trouble free.  Well almost.

In May 2014 I had a failure to feed (shell kicked up on the lifter but stuck at the chamber entrance) near the extractor, but I figured it was a dirty gun.  Cleaned the gun up and it shot fine in a practice session.  Since then I am experiencing 3-4% of Federal Multi-purpose (Walmart) failing to chamber.  Occasionally I can bump the bolt handle fwd and it chambers, but sometime I have to rack clear and re-rack to load the next shell.  I thought it was the Federal (which admittedly has some weird crimps recently) until one Winchester AAs and a few Remington STSs didn’t chamber.

I pulled the barrel during a match and found a tiny (1-1.5mm) spur near the extractor on the inside of the chamber.  I cleaned that off with a knife during a match and the gun ran fine for the next 9 shell stage.  I polished it after the match with Mothers and a dremel.  Punched 9 shells through it (including some that has previously failed) and it ran fine.  Next match, one failure (Federal multi).  At my last match it had one failure (Federal multi).  

This weekend I tore the gun down to clean it I found that the ejector on the barrel extension was loose and could be rotated.  See photo --



I called Mossberg and they returned my call the same day.  +1 for CS.  I explained what I was experiencing and asked about a weak recoil spring.  The female CS rep said the recoil spring should be fine, but the ejector could be the problem.  She said it’s welded/soldered in, but should not fail in 3k rounds.  Despite being out warranty (2 year) they offered full replacement of the barrel.  I lobbied for repair vs replacement  and she said that was possible.

So after 2,500 rounds I kinda know where my shot, slug and buck are going to hit.  The gun fits me well and I am lothe to roll the dice on a new barrel, new patterns, new POI with slugs, right?  For now I have blue locktite on the ejector, but it may go to Maverick Arms in TX in December for some pro TLC or I may get a local smith to silver solder it.   I’ll keep shooting and checking it.  If it stays put and my FTFeeds go away we’ll all be smarter.

Mossberg has been pretty good with CS from what I can tell. Had an issue with my 500 this summer and they sent me the replacement parts no questions asked. I originally called to see were I could buy the parts since I have had the gun for years and knew it was out of warranty, even mentioned that to them when I called. They sent the parts free anyways.

I want to resurrect this thread to Mea Culpa.

Turns out my feed problems were due to my lifter.  The lifter I had welded by a local machine shop, not a gunsmith.

It was not the Wally bulk Federal (although some of it had some very questionable crimps) and it was not the shell ejector (which is now loctited in place).

I recently added a Southern Kentucky Tactical lifter to my JM and it is running perfectly again.  

C.J. Smith at SKT is extending the lifter and bending it down slightly at the tip.  He's a 3G shooter and has perfected this design.  It makes loading deuces and quads easier too, once you open the port and shave the forearm down.  I recommend your contact him to weld yours or just buy one from him.  You won't be disappointed.

https://www.facebook.com/skytactical

My JM has about 3k rounds through it and should be GTG this season.  Purchased in April 12.  Only other issue was the OEM mag follower sticking, so I replaced it with a Nordic barrel follower in '12.

He perfected the design? C-rums has been welding lifters flawlessly for about 10 years now; including mossbergs

Why bring C-rums into this? I think he was just trying to compliment the folks at Southern Kentucky Tactical.  But I can also vouch for their work, they did a perfect job on mine as well.  There are quite a few folks out there who can weld a lifter.. if anything, I think the advice is to take it to someone who knows what they are doing and how the part will fit the firearm.

Nothing against Crums intended.  I should have asked Jeff to weld mine 3 years ago instead of going the local (not cheaper) route.  

But I do think SKT has perfected the lifter for the JM pro.  I know CJ looked at (and maybe ran) Jeff's design.  Then CJ improved it with his own changes.

Crums is still probably the king of M2, Versamax and FNP lifters, and adding Beretta's and Stoeger's.  So full credit is due there.

Many would be unhappy shooters without thumbnails if it wasn't for Jeff Cockrum.

I would agree with other here that SKT has a better design for the welded lifter than CRums for the 930. CRums was the 1st, but there are things I wanted done to mine that he wouldn't do, like polishing the lifter after it was welded. The slight downward bend that CJ does to his lifters also makes loading easier, and helps keep the loader out of the way completely while you are loading. I have used both CRums and SKT's welded lifters and would buy SKT's every time.