>Mossberg Disassembly Guide Pt. III<
This is the shell lifter. It is what drops down to pick up the shell coming out of the magazine, then lifts it up to the bolt. It should be fairly loose now.
The shell lifter has two pivots, one on each side of the receiver, where I am pointing at.
To remove the shell lifter, raise it up and squeeze it together until you can get the pivot pins out of the holes in the receiver. Then just lift it out.
Once the shell lifter is out, the bolt assembly just pulls straight out of the receiver. You can see the two spring-loaded extractors (held in place by pins). Clean these so that they move freely. If they get crud trapped between the extractor and the bolt body, the extractor may slip on the shell rim and you get jams.
You can also see the firing pin. It should be clean and move freely in the bolt. The bolt ramps are what locks in to the bolt slide and cams the bolt up to lockup with the barrel when the action is cocked. It should also be clean. A little gun oil here will work wonders on how the action feels.
This is the tang safety. The Maverick 88 won't have this. This safety is held on by the small flat-blade screw in the center. There is a small steel ball pressed into the receiver under the safety knob. It shouldn't come out, but it might. Before you remove the screw, look inside the receiver and see how the metal safety hook is pointing. I like to touch up the red paint in the safety "Fire" position.
When the screw is unscrewed, the safety hook falls out.
Here are the pieces of the safety: there is the plastic knob, there is a metal spring plate that is under the plastic knob (has holes in it), there is the screw, and there is the safety hook.
This screw holds in a small metal piece which is the ejector. It is what pops the spent shell sideways out the ejection port. Remove the screw and the ejector should just lift right out of the slot it fits into. Take a look at this and make sure it isn't bent, that the slot isn't full of crud, and that the hook on the end isn't worn out. With the bolt removed, the ejector should be sitting with the end furthest from the barrel up higher than the slot. The ejector pushes down when the bolt moves past it, then springs back up to catch the rim of the shell and flip it out the ejection port.
Here's the ejector. Check it over for cracks or wear. It should be fairly stiff but springy. Often a weak or worn ejector will cause jams as the spent hull does not leave the chamber. New ones are not expensive, and bending a worn ejector will only work for so long.
To remove the buttstock, first you have to take off the recoil pad. This is usually held on by a couple of Phillips screws. Just stick a screwdriver in the holes in the pad and feel for the heads of the screws and unscrew them. You can see the screws in this picture.
The buttstock is held to the receiver by a longish, largish screw. Some of them are Allen headed, most are straight-blade screwdriver slotted. You need an extra-long 1/4" blade screwdriver to reach to the bottom of the buttstock to remove the screw. Then, the buttstock just pulls off the receiver.
The receiver should be checked for damage, cracks, and wear. Ovaled shell-lifter pivot holes are possible. While the receiver is not stressed to chamber pressure in the Mossberg design, it is still possible to be damaged by mishandling or abuse. All the slots and grooves in the receiver should be cleaned and lubricated with gun oil. All the pieces of the gun should be cleaned and checked for damage or wear before reassembling. I have seen where action bars have had the spotwelds that hold them to the action slide break loose, usually from somebody trying to "Hollywood" the action (one-handed cocking by flinging the gun up and down) or on heavily used & poorly maintained guns. It's normal for some side to side slop on the action slide as it sits on the magazine tube, and some twisting looseness is normal.
Re-assembly is the reverse of dis-assembly. Use caution and function test the gun after putting it back together before you put it back into service. I use a couple trimmed, empty shells to test for feeding and function before using live ammo. Above all, check the function of the safety and trigger parts to not fire if bumped, slammed, or banged.
The Mossberg pump is a simple, durable gun, and if maintained properly, will provide years of service.