Originally posted this on the shotgun forum before I realized there was a separate forum for repair.
My 935 gave me some trouble earlier this season, took me till this weekend to straighten it all out. Did quite a bit of research and did not find the exact same problem on the net, but some similar. This site was especially helpful in working it out so I figured I would share what I found.
Just so we can put things in perspective, I do more upland hunting than waterfowl, so when I went to buy a semi-auto I was looking for: 1. Tang safety, B. Synthetic stock with camo, 3. Quick change to a cantilevered slug barrel for deer.
Truth told I am not crazy about this gun, it does feel like a 2X4 to me, but it fit the bill and I wanted to give the 835 to my son...after shooting a double for so long, I tend to dislike pumps...but my son loves that click-clack so he can have it.
So the problem was the gun would not fire and 3.5" shells would not slide into the magazine. There were no imprints on the primer, but the trigger would click. I painfully sat on the X (no decoys even) and could not get the gun to fire even as a single shot.
I had cleaned/lubed it up at the close of last season and stuck it in the locker. I USED to use Rem oil, that will now change.
After it stopped working took it all apart at home to see what was wrong. Lube was now not the only problem. The bolt would not close all the way. This was stopping the hammer from reaching the firing pin, and also stopping the shell lifter from moving all the way up which would not allow shells to slide in the magazine. Thanks to some advice on this forum, I slapped some valve seating compound on it and cycled the bolt about 100 times while watching "Dances with Wolves". Maybe 200, I lost count when the cavalry came back to the fort.
Cleaned and lubed everything, for now I am using Quaker State 5W30 Synthetic thinned with some MMO and Kroil. CLP Breakfree is on my list to try. Not sure what I am going to do with the Rem oil stuff I have.
It cycled beautifully, but still did not close the bolt all the way. The extractor/ejector arm was not moving much. The spring loaded piston that keeps tension on the extractor was stuck in the forward position. This is where I get real torqued at Rem oil. The Rem-oil apparently did not seep in between the piston and the hole. Out comes the Kroil, still does not budge. Really trying hard not to break anything, but I am running out of options. Out comes the hammer
. Using the smallest ball peen hammer I have and some pipe pliers I smaked the extractor on my wooden bench until it moved. Now we are stuck in the rearward position. Broke out the propane torch
, heated the bolt until the Kroil boiled a little. Still no movement. Hammer time, smacked the bolt
until the piston came out again. Repeat until nauseaus and/or mentally exhausted. Have cigarette to chase Kroil fumes out of lungs. Add more Kroil to gun and finally things start to work. Add even more Kroil and wipe with paper towels to remove as much rust as possible.
I think it's ready, have not had the time to fire it.
Lessons learned: Rem-oil was apparently not made for guns. Mossberg 935's need a little help with metal fitting. Mossberg 935s need good oil on the extractors.