Mossberg 930 FTF

[checkenbach]

I have a Mossberg 930 that I've been using for 3 gun and the occasional round of trap. I was at the range shooting some trap, shot a few rounds and the gun choked, click, no bang. Chambered another round, nada. Went to the truck, got the backup unit, finished the match.
I took it apart, and expected to find a firing pin, or spring issue, it looked OK except for the hammer had a bit of off center strike wear to the firing pin.
I cleaned it and put it back together and took it out Sunday, I fired one before it choked again.
I did some searching on the net, and found a thread about 930's not going into battery due to the piston being full of crud. I took it apart again, and found the piston about 1/8" from being seated, and very stiff.
I took the piston apart, and was amazed at the crud that came out of it, inside and out of the gas rings. I cleaned it up, and put it back together, the piston would almost drop into the barrel under it's own weight. I will shoot it soon to see if it's fixed, but I'm confident it is. And I'll be doing a bit more thorough cleaning, from here on in.
1st pic is the crud that came out of the gas rings, 2nd pic is how far out of battery it was stuck, 3rd pic shows normal battery position.

[SubieRX]

I've got a 930 that I use for skeet as well. Those pistons get filthy! For the most part, my 930 has performed extremely well. The only times it seems to have hiccups is, like in your situation, when the piston is super dirty.

Keep her clean and have fun shootin'!

[a1rfreshener]

mine only gets failure to eject wen the piston is that dirty...I usually run it as dry as possible. since oil attracts grit.

[JaMail]

wonder how t9 would work.

http://boeshield.com/

[a1rfreshener]

sounds amazing, do u think instead of it sticking to the piston it would be blown out the gas ports? however...my 930 is cleaned after every use. and it never really gets that bad unless u shoot into the hundreds...depending on shells and wat not..and wen i need to do a field strip i usually just take the barrel off and take the piston out and bang it against something metallic to break lose all the buildup and let it fall out.