NEED A MACHINIST / METALLURGIST

[30calpal]

My Win 100 needs a new gas piston /cyl.  My SIL is V.P. of a machine /fab company and can make the parts 'custom' for me.  I want something that is corrosion resistant and tough.  Question 1) is 416 S.S. the best material to use?  If not, then what is (nothing exotic please)?  Is heat treating required?  Q 2)  How close tolerance should the piston fit the cyl without the cyl 'biting' the piston once a few shots have been fired?  The Win 100 auto gas system look very much like the M-14 system, except that the Win 100 system is all concealed in the forearm, the M-14 cyl is exposed out in front of its forearm.  OK, some of you with this kind of experience jump in and tell me what material and how close the fit should be.  Thanks.  Oh, you cand PM me if you prefer.   

[gunnut69]

Brownells used to carry the replecement cylinder for the 100, if they still do I would surely go that route.. Those I've seen were silver brazed on..Brownells has an online catalog.. Luck.. Just a question please, What told you there was a need for a replacement piston?

[trotterlg]

The problem I see with stainless is that is tends to gall up when used against it's self.  Even 413 is not totally resistant to rust or other bad things.  I think I would just have it made out of what the factory figured was best and made it from.  A new factory part is probably you best choice I think without a lot of experementing.  Larry

[Victor3]

Those I've seen were silver brazed on.

 If that's the case, I wouldn't use any kind of stainless. Silver brazing stainless can be an excercize in frustration even if you have the correct rod and flux for it. It's not nearly as easy to do sucessfully as with brass or carbon steel in my experience.