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Fixing A Mossberg 930 Feed-From-The-Tube Problem

Fixing A Mossberg 930 Feed-From-The-Tube Problem
By Larry Weeks, Brownells Public Relations Manager
 

Why does bad stuff always happen at a match? I picked up my new Mossberg 930 JM, shot a couple of rounds of trap, patterned it, shortened and modified the stock, shot slugs through it and thought I was set for the Ozark 3-Gun Championship.

Guess not. The first (and every) time a stage required an empty chamber start, I couldn’t get the first round to pop out of the 9-round magazine tube and load into the chamber. With one or two rounds in the tube, everything worked fine. Put in 9-rounds and I had to rack the bolt handle four or more times before it would feed. Once the first round was out, everything ran fine. It was just that first one that was a problem.

I overheard another shooter talking about the same problem. He said he’d taken the magazine tube off and polished the end of the carrier latch through the front of the gun to solve the problem. Looking into mine, going through the magazine tube opening seemed awfully tough. Luckily, Mr. 930, Jerry Miculek, was also shooting the match, and I asked him about it. He told me some of the guns have that problem, others don’t. Polishing the tip is the cure.

He also gave me a pointer on how to get the carrier latch out of the gun. There’s a small slot, just below the latch (Photo 1, below). The pivot/retaining pin for the latch passes through that slot and is held in place by a little bitty version of what I’ve always called a “hitch pin”. Jerry suggested using a flat pronged automotive fuse, and putting a 90º bend in it to slip into the slot and slide the “hitch pin” out of the way.

While searching my shop for a fuse, I noticed a scrap of aluminum left over from another project that looked just right, and it already had the needed bend. I Acraglas'd it into another piece of shop scrap (Photo 2, below) to make a tool in case I ever had to do this again.

Here’s how I did the job. Make sure the gun is unloaded and there’s no live ammo anywhere near the area (of course!). You’ll need to disassemble the gun and get the bolt out of the way. Once that’s done, this is the procedure.

1. Insert tool into slot in front of the pivot/retaining pin.

2. Slide tool to rear, pushing the “hitch pin” out of the way. Make sure you get the “hitch pin” all the way off the pivot/retaining pin. (Photo 3, below)
3. Place a piece of tape over the slot where the “hitch pin” has been moved to (Photo 4, below); you don’t want it falling out and getting lost!

4. Put a bend in a paper clip so you can get past the parts of the action that prevent straight shot access to the top of the pivot/retaining pin (Photo 5, below).

5. Insert the bent paper clip through the ejection port and use it to push the pivot/retaining pin partially out of the hole. If it doesn’t move easily, make sure the “hitch pin” is completely off of the pivot/retaining pin. You may also need to push on the bolt release button to release or change the tension on the pivot/retaining pin.

6. Once the pivot/retaining pin is partially out, grab it with your fingers or small pliers and remove it.

7. Lift the carrier latch out of its recess. Be careful, there is a small coil spring at the back that is only held in by a spot of grease.

8. Polish the flat end of the carrier latch. I used 600 grit wet/dry paper on a hard, flat surface (Photo 6, below).

9. Lightly break the sharp edge at the end of the carrier latch. I also rounded the corners ever so slightly, just to eliminate sharp edges that might dig into the brass of the shotshell (Photo 7, below).

10. Clean up the latch and reinsert it into its recess.

11. Start the pivot/retaining pin into the hole in the receiver (Photo 8, below). The two times I’ve taken it apart I’ve had to move the carrier latch back and forth a bit to get the pin to go into the top part of the hole, above the carrier latch. You don’t need a hammer; the pivot/retaining pin will slip in with little resistance.

12. The pin will be slightly below the surface of the receiver when its slot is lined up to accept the “hitch pin”.

13. Use the 90º tool to slide the “hitch pin” back over the pivot/retaining pin.

14. Reassemble the gun and test it using dummy ammo before heading to the range for live round testing. I turned my gun on the left- and right-side and upside down and it fed fine when fully loaded with 9 rounds. I’ve done at least a dozen tests, between dummies and live rounds and had no failures to feed.