For those who are interested.
I finally had a Sunday that I could spend in the garage at the work bench to fully disassemble and clean the Snow Goose.
Just to put it in context this semi auto 930 Mossy has not been cleaned since December of 2021. Now it’s March 2025 and 500 plus rounds later.
Honestly, It was a huge PITA. I started at 3:30 and had all the bits and pieces “cleaned” at roughy 8:30. I say “cleaned” because I think I should do it a second time. I may never get it truly cleaned to “showroom” again. I still have not put it back together.
Here are the highlights/lowlights of my 5 hour spa day with the Snow Goose:
The barrel was hard to remove due to all the gunk and carbon build up. I did get it out with some much more than normal force.
The forearm/hand guard was dirty, especially on the inside. Good thing I have a 32 oz bottle of Hoppe’s. It was absolutely filthy. The light brown discoloring does not come off the ghost wraith finish with any of the solvents I have on hand.
I hand to use lots of hopes and scotchbrite to clean the magazine tube. Tube was loose as well. I have not cleaned inside the tube at this point.
The trigger group was not so bad but still required a fair amount of work with patches and Q tips. Dirt and gunk had made its way back this far.
The bolt, bolt carrier, link and link pin were dirty and required a good cleaning.
The inside of the receiver required a good cleaning. This is always difficult to do.
The barrel and cylinder were the worst. Inside the cylinder there was such a carbon built up on the taper and at the bottom of the taper where it hits the cylinder wall that I was surprised the bolt still went into battery. It seemed to accumulate heavier at the 4:30 to 7:30 segment. This makes sense since the gas is blowing down. It was tough to remove and it’s still not 100% in my eyes. I had to use lots of solvents and various brass instruments to chip, scrape and brush it off. It’s ok now and the piston runs smoothly in the cylinder with full travel. This was by far the most time consuming spot.
I disassembled the factory piston and soaked the 3 pieces in Hoppe’s. I soaked many of the smaller pieces in a small container of Hoppe’s as well. It was a lot of work to get these three pieces back to “normal”. Scotchbrite and a brass brush for this.
The barrel was a BITCH. I ran a wet patch down the barrel, waited for 10 minutes or so and then the hit it with the brass brush. I did this probably 5 or 6 separate iterations. I must of brushed over 150 strokes. I finally managed to get it acceptable.
I used a pipe cleaner on the two gas ports. I went in from the cylinder side.
The choke came out fine and cleaned up easily. There is a ledge inside barrel that the choke sits on when in position. I could not get down there and clean it out as thoroughly as I would’ve liked. I need to find a way to do this. Probably the brass brush for scouring the barrel will work.
All of the components down stream of the piston (spacer, pusher assembly, spring, forearm retainer) were filthy but cleaned up well.
Conclusions:
I’m going to install the SBE SS piston and a Mossberg NiBo coated one piece outer seal ring (JM930 pro outer seal ring) when I put the SG back together. We’ll see what improvements that brings. In my opinion the factory 3 piece assembly did the job nicely. The new unit should be easier to clean at least.
Spring is around the corner so I’ll clean the SG again to try and get anything that I missed. Then I’ll lube her up and put her away until the snow flies next year.
The next time I put 500 and beyond rounds through the SG I’ll need to do it in a much shorter amount of time so the carbon build up may be easier to clean. Maybe an after range wipe down to keep the build up from accumulating.
Use a pump or a double barrel and save a lot of time!
Below are some pictures for the curious. They aren’t for the faint of heart!
