I am looking into buy a 7mm STW, I have found one in Sender and on in Classic M70 from Winchester as well. The Win has been beeded and free floated and a brake installed. What would be easier/cheaper to perform a full accurizing job on?
A lot depends on what the smith you choose likes.
They both can be accurized very well and make fine Custom rifles.
Me personaly, I like the round shape of the 700 Rem for accurizing best because if the action
is not perfectly true (Concentric) To the bolt the Outside of the Rem action can be turned true
on a lathe. The flat bottomed actions like the winchester, ruger, Weatherby and others can't
be trued in this manner.
A lot of old bench resters use to turn the 700s and sleeve them to a much larger Diameter
for maximum strength (To hold a huge Bull Barrel that is full floated) But now you can buy
larger custom actions and this practice is not as common any more .
The other reason that I prefer the 700 Rem action is that there is a lot more available after
market parts to customise to your taste.
I build rifles on all types of actions and the Remington is one of the easiest and consistently
more accurate actions that I have used.
In the right hands almost any action can be made accurate but some are easier that others.
PS; The Remington Sendero makes a fine rifle to build on or accurize.
Hope this helps
J E CUSTOM