Part number from Brownells should be 655-002-100 for a Nu-line Win 100 gas piston....If memory serves me right there was a recall for an upgrade on the Mod 100 from Winchester and it must be still available as I was at the ProBassShop in Springfield, Mo and the gunsmith shop had the modification listed on the wall

Brownell's sells a replacement part, I believe made of stainless which should solve the problem

SRT, Thanks, that is super good news! I was wondering when the rifle opens up, just what would be left of it, and how reliable it would be after a clean and polish.

308Sako, If it`s to late to save your stock, MPI makes a nice fiberglass for the M-100! I have one on mine, and it`s a (Big) improvement! I have a stainless steel gas piston in mine also, that I orded from a Mi. gunsmith- Bob Gardner! His ph# was 616-792-9307, but I don`t know if he still makes them! Ed

Thanks ELB, I do believe that's the problem. I returned the rifle to it's owner the other night and instructed him as you suggest. Time will tell, thought I think a new stock will be a part of this project. Thanks again

Still frozen, and the Kroil is soaking in everywhere possible. The action doesn't seem to be the problem area, more likely the symptom! The gas piston would appear to be the culprit at this time. The bolt body has some slight mobility via the magizine well, and the bolt head would appear to want to rotate if allowed the motion. Yes Jim these rifles are the worst nightmare if left unattended and to their own devices. Thanks to all for the guidance, and may your prayers be answered wheever they are offered. Still on this one!

Thanks Jim