Mossberg 500 Slide Locks After Firing - Thoughts?

[elmo]

Hey Guys,

I've had this shotgun for a while and it always seems to have this issue. It appears to occur on about 50-75% of shots fired. After firing a round I can pump it. I would have to press the slide release to eject the round and load a fresh one.

It's a Mossberg 500 with 18" barrel and a knox spec-op. I've heard it's about how you hold it, and I've held it many different ways and no luck. I've fired at least 500 rounds through it at this point. Any thoughts?

Trying to see what ou guys can come up with before I ship it into mossberg for servicing.

Danny

[Hayashi Killian]

Have you disassembled it at all? If so, make sure you're lining up the bolt, carrier and action rails properly. It can be difficult to do, but make sure the entire action moves smoothly before putting the trigger assembly back on. If you push down on the carrier, the entire thing should slide together with only a little effort. Make sure there's no gunk stuck in the receiver or on the action rail slots on the receiver. It might not hurt to give the rails and inside of the receiver a dose of lube (I used Breakfree).

[elmo]

I've disassembled it a few times. I think i followed a long with a you tube video i saw. After cleaning I would put it through a few rounds using snapcaps to make sure it functions properly and it appears too. but at the range with real rounds it's not the same.

[Hayashi Killian]

Check your action bars for any signs of wear or warping. It's possible they're bent a little and not cycling properly. Are you short-stroking it or are you pumping it hard? Remember that pump-actions are meant to take abuse, so don't be gentle.

[MossbergMan]

Questions: Does it ever allow you to cycle the action after firing a live round?Is this a "new" problem to the gun? Have you called Mossberg about it?
If it operates with the action release, but not with the trigger I suspect a couple of issues. One is ammo/chamber related. Another is a broken part in your trigger assembly and lastly, if this is an intermittent problem it may be as simple as you pulling back on the forend while you fire. The Mossy will not unlock if you are applying rearward pressure on the forend after pressing the trigger (only Winchesters are designed to unlock like that). You may not be pulling back with dummy rounds because there is no recoil.
Just some random thoughts, hope it helps.

[pTa]

try pushing fwd on the forearm before pulling it back