Wow, you resurrected a 7-year-old thread??
With regards to stainless steel, there are a lot of different types of stainless steel. Barrels are typically made of 416 stainless which is a martensitic stainless and quite easy to machine. Some of the austensitic steels tend to work hard very readily and need heavy cuts with a big machine or they will go rock-hard on you. Fasteners are typically made from 304 ss and it is prone to work hardening.
As far as using a CM barrel, I use them occasionally myself. They are stronger and can be blued if that is the type of rifle you are building. Who wants a SS barrel on a exhibition grade rifle?
I much prefer CM actions over SS too.
I'm no expert on barrel life but I'll bet if you don't ruin it with a cleaning rod, 20-30K out of a 22 rimfire is no problem. Out tactical rifles typically went about 4500 rounds (308) before needed new barrels. I have worn out two 6.5-284 barrels in less than 900 rounds and one in 500 rounds. I think R17 is really hard on barrels.
