Mossberg 500 Pump Action Troubleshooting

Re: 500 barrel issue **pic added**

Yea I dont like it either. Im almost positive it wasnt like that before.

Re: 500 barrel issue **pic added**

and if you compare chamber ends of the two barrels ? do the look identical ? look for sight bends or some build up inside the reciever .....

Re: 500 barrel issue **pic added**

Yes, they look identical and their arent any noticeable bends. I contacted Mossberg and Im sure theyll resolve this issue for me but it is a little disappointing because the gun is like new.

Re: 500 barrel issue **pic added**

I would have to hold it to try to help ya, sorry. Hope you get it figured out and let us know what you find out

Re: 500 barrel issue **pic added**

It has to be the barrel. I took it off 50 times and tried to get it on straight but it must be tweaked. Like I said the rifled barrel falls right in like butter so I dont think it has to do with my inexperience with shotguns.

Re: 500 barrel issue **pic added**

Hope OFM gets you taken care, I can't offer much help from here.

Keep us posted.

Re: 500 barrel issue **pic added**

I don’t know but my first thought was something happened to your smoothbore barrel while you were running the riffled barrel like the tab with the square hole in it that runs off the chamber, got tweaked somehow......possible ?
That’s really the only thing that can set the barrel off like that because you already know the receiver and you install skills are good as you can install the riffled barrel fine. All other possibilities eliminated it has to be your barrel, something about it you’re not seeing.

Re: 500 barrel issue **pic added**

Yep

Re: 500 barrel issue **pic added**

That's exactly what I'm thinking happened. And whatever it is can't be seen by the naked eye.

threads for pictinny rail?

does anyone know the thread size and length for a picatinny rail?

i ordered a kit from optics planet and they gave me the wrong screws and they are too bug of a hassle to get the correct screws.

if any of you guys know the size please let me know


thanks

Re: 500 barrel issue **pic added**

I'm new to Mossbergs, but I believe the barrel extension (the rear part that actually goes into the receiver and the bolt locks into) is threaded or pressed onto the barrel. I think it is possible this extension has turned on the barrel slightly. Is this a possibility?

Re: threads for pictinny rail?

Dang, I used to have some but don't anymore to be able to measure them.

Uhh, maybe I can at least find the thread pitch in a seearch. Ill come back to this!

Re: porting

how much does porting usually cost? i need to port a 18.5" after seeing all the benefits

Re: threads for pictinny rail?

What I found says they are an 8/40 thread pitch and it gave a torque specification of 15 inch pounds to prevent damage. I never did that, just was careful...

What it didn't tell me was how long the 4 screws should be, but if you have some on hand, you may be able to use those for reference.

Re: 500 barrel issue **pic added**

Hmm I'm not sure. Hopefully someone can chime in. That sounds like it could be causing my issue

Re: 500 barrel issue **pic added**

I would check out your extractor and see if the tongue that fits into the barrel lug slot has bent.
It may have happened while shooting slugs in the slug barrel.

It is a crazy idea, but all I got at the moment.

Re: porting

Porting a shotgun will reduce the muzzle climb and muzzle flash.
Rossignol has posted a couple videos of some test shooting he did. It is amazing how the muzzle climb is almost eliminated and the muzzle flash reduced.