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Maverick O/U Troubleshooting


Staff member
Any issues, concerns or problems you may have with your maverick O/U; this is a thread for troubleshooting.
Re: Maverick O/U Barrel separation

We were shooting rep on the weekend with federal trap ammo and it blew the bottom barrel out. Anyone know how I can get Mossberg to do something about this? They have been unresponsive to my emails.

I have pics but am not sure how to post them on here.

welcome to the forum from NY.
sorry to hear about your problem. contact Joe at mossberg. he has helped out quite a few MO members.

Joe Zakher

keep us posted.
I bought three of these. One had manufacturing defect. The bottom barrel was not set all the way in. It protruded a fraction of an inch. As a result the gun was extremely unreliable. Much of the time it would not cock when opening the action. From the same cause there was also a gap in the chamber region. I returned it to the company. They promised to replace it, but it has now been seven months and nothing has happened.
Update: Mossberg eventually replaced the defective gun, but it took 10 months. In the interim I actually bought another (a fourth) for my son to use. Now I have an extra one.
This may sound like a dumb question but I'm not sure what the sight picture is supposed to be. Am I supposed to bury the front post all the way down to the bottom of the rear so it's sitting on the bottom of the groove OR should it be lined up with the top of the rail? Having it down low feels less comfortable to me.
I have been doing some research on o/u actions (types/function) and the issue the Maverick HS12 (stiffness only when cocking the hammers) is because they used the same springs from the longer barreled (Maverick Hunter 28" barrel)

Do a spring check. Open the gun after it has been fired, then close it. Open it again without firing it. Was it easier to open? If it was easy to open you need to put some weaker or shorter springs in the gun. Then it will be easy to open.

I will be cutting off a single coil at a time and see the difference in the ease of the "cocking the hammers" before deciding if it needs more.