I bought a S&W 1000 Semi Auto 12 gauge with 2 3/4 chamber. I cleaned and inspected it cleaning it thoroughly and put in a new rubber Piston Shock Absorber.

Took it out to shoot at the range and it would not fully close the bolt after it loaded the next round. I would have to put back on the operating handle and then push the button to release the action to go forward. I was shooting 32 grain 2 3/4 slugs.

Any idea why it would not fully cycle the next round?

Breech bolt and associated parts need oiling?

Does the piston move freely the full length of the slot in the magazine tube?

Thank you for the response.

The piston was sticking. I used steel wool and a scotch brite pad to remove some burs in the mag/gas tube.
As I would slide the piston back towards the Pressure Compensator Valve Assembly it would stick.

Now it will slide allot easier.

What lubricate would be best to use inside the tube? I have read that oils seem to deteriorate the Piston Shock Absorber and will collect carbon residue.

DO NOT LUBRICATE the piston or tube.

Darn, I took the shotgun out and fired a few rounds and still doing the same thing.
Not going fully into battery.

I thoroughly cleaned the shotgun, oiled the breech, insured the piston moved freely along the whole slot in the tube.

Also, this time I used slugs that were 1600 FPS as last time they were 1375 FPS.

I am at a loss how to fix this.

The problem is probably the o-ring recoil buffer. They have a tendency to turn to goo after a while. I replaced mine and after one failure to eject, it began cycling perfectly.

Well that is a bummer.

Make sure the barrel ports are clear.


Pull the trigger group and check for extreme buildup of gunk at the back of the receiver.
Also check the the nylon insert at the back of the receiver has not come loose and moved out of place.


Good luck,
KO

I had one and loved it...started something similar to this IIRC....have you pulled the buttstock to be sure the tube and spring are clean and free??..is the front of the bolt clean and smooth? is the chamber in the barrel free of plastic buildup? nothing built up behind the magazine release??...just a few thoughts

Thank you @ko41 and @Babysitr

I did send it out for a gunsmith to check out. Once I get it back I will check it out and provide feedback.

Terrific guns. Probably Mossberg's best looking auto Well worth the money. Mine is an 1000M which is a 3" Magnum with steel barrel and receiver.

Might want to doublecheck that weight. A 32 gr 12ga slug would exit at about 10,000,000 fps...pretty sure you mean grams

__________________
aka "Mooncat"

image_2021-03-22_133833.jpg

Box read 32 Gr 1 5/32 OZ for the slug I originally was shooting.

Thanks

I ordered a new "Action Spring" from Numrich and will try that.

Also, how do you remove the magazine follower? It looks like to me you will need to remove the magazine tube to get the follower out. But have not came across any information on that.

Along with that any instructions on magazine tube removal out there?

There is a lip machined into the magazine tube at the receiver end to keep the follower captured. I do not know if you would be able to force the follower past the indentations for the magazine spring retainer at the muzzle end. If the follower is broken already I guess it wouldn't matter if it came out in pieces. I think you would be able to push a new follower past the spring retainer indentations without much problem.
From what I have read, the magazine tube and magazine tube lock nut both have thread locker applied and are difficult to remove.

http://smith-wessonforum.com/136112971-post5.html

KO