Mossberg problem.

[Guns and more]

I have a Mossberg 500.
I took it to the range and had the following problem:
When I release the foregrip and rack a shell into the chamber, either two try to escape and jam, or one falls out of the ejection port.
Either way, it doesn't fire.
After it is fired once, it seems to work fine. But I can't trust it as it is.
It's new.
Should I:
Shoot it more to break it in?
Give it a good cleaning and oiling?
Tweak the elevator?
Leave it loaded to compress the spring?

It seems more than one shell is released when I rack the foregrip.

 

[mnrivrat]

Start by making sure the last round you put into the magazine is seated completely past the shell stops.

It is the shell stop/interuptor area that will creat this type of feed failure. Sometimes they need adjusting .

 

[RaceM]

Since it's a new gun do a strip down & check for burrs on the cartridge stop and interruptor. They're just stamped pieces and can have rough edges on the corners from the stamping process which can possibly hang up against the receiver rails. As Rivrat said, make sure your last round in the mag is fully seated.

 

[dak0ta]

This happened to my M500 once during sporting clays. It was due to my magazine tube coming loose. Make sure it's screwed in tight with some blue loc-tite.

 

[Yo Mama]

Start by making sure the last round you put into the magazine is seated completely past the shell stops.

This is most likely the problem.

 

[Guns and more]

I will. Thanks.

 

[B yond]

Is this with normal, name brand ammo?