Mossberg chambering connundrum

[Inquisitor]

I just received a Mossberg 500 in 12g today, with 3 snapcaps to mess around with. After assembling the barrel to the receiver and removing the limiting dowel in the magazine, I loaded up 2 snapcaps. Cycled and ejected beautifully. So I loaded up 3 snapcaps to get more practice (first shotgun ever) and to my great fustration, it jams. After much experimentation, I determined that the shotgun cycles and ejects great when I put 2 into the mag, but always jams when I load 3.

My thought and observation is this: When I load 2, the spring isn't as compressed as when there are 3 or more in there. When I try to chamber a shell with 3 loaded, the spring shoots 2 out of the mag; the little metal clip that holds the shells in the mag isn't resetting after one shell passes by (hopefully you ppl know what I mean). The result? Two shells trying to get into the chamber. One of them usually falls out. Yay.

Help me! Has anyone encountered this? What should I do?
Thanks.

 

[Ceska]

I have found the same feeding issue for older mossberg 500's. They can be picky for ammo.

 

[Workin Man]

Just because it does this with snap caps doesn't mean it will do it with live ammo. Compare the rim on your snap caps with the rim on a real shell.

 

[Boomer]

Disassemble your shotgun and spray out all of the recesses in the receiver and all the components with a product like break clean. Check the surfaces around the magazine opening, and the shell retainers and receiver recesses for burrs. Reassemble and see if the situation is resolved.

 

[Calum]

I agree with working man, Snap caps can be the problem.
Take her to the range and try some real shells.

 

[thebuckhunter]

Is it possible that you're short stroking the gun? I have a Mav88 with zero feeding issues. From the cheap stuff to the good stuff, hi and low brass, no brass (activ), field to magnum loads.

-Jason

 

[gak]

If you've cleaned and oiled it after bringing it home from the store/wherever, don't assume anything until you've shot a few boxes of different brands of ammo through it.

Some snap caps cycle, some double-feed every time.