JM Pro feeding problem.

[billdogg]

I'm having an issue with my 930 JM Pro. With a closed empty chamber, I pull the charging handle back, and the shell is stuck on the shell stop, and won't push out onto the lifter. However, with the bolt closed, I can push the lifter up, hit the bolt release, and the shell catch will move enough to release the shell. Any ideas?

[HeyChris]

Have you taken a look at this:

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

[mpom]

Have done that mod, plus changed the shape of the vertical inside edge of shell stop from straight to a curve, mimicing the curve of a shell rim, so the shell is released more easily.

[AirForce2]

There are multiple areas that could cause this issue. Some items to check:

How old & how many rounds thru the gun?

-make sure to either remove the shell stop assy and ensure no debris is stuck behind or spray, pick out any if not removing shell assy to inspect.

-if the tube spring is to strong & long, this can either cause to much pressure against the front of shell stop. Spring should be appx 14-15 inches past the tube w/cap off (20 is to long). Mossy stock spring should not be 20-22 inch past end of tube (even if you have added an additional ext the same rule applies). If you switch from stock mossy spring to nordic, the spring should be cut down to appx 12-13 inch max since nordic springs are much thicker & stiffer.

-look for any burrs on the bolt track that rides against the shell stop assy (this is what allows the shell stop assy to tilt in & out during cycling)

-You may need to polish the front side of the shell stop assy and the sharp edge a little more (not file, polish and form)

-see if anny info on the giant mossberg JM Pro post gives to any insight. Pay special atten to the pics of the new mossy trigger assy diff vs the one that came w/mine. Good luck.

[DaveG]

I had this problem, there was a piece of brass caught under the shell stop. I removed it and been working fine since...

[RobSky]

Have you taken a look at this:

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

Knock on wood, this fix worked for me. Thanks Chris

[Triggerbender]

Have you taken a look at this:

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

Knock on wood, this fix worked for me. Thanks Chris

+1 and had to add a Wolff Xtra power mag tube spring so far so good, knock knock!