Shank length and contour questions... Building a 6.5 Creedmore on a large shank action (long story)

I have this Large Shank (started life as 270 WSM) action. Its a 7mm RSAUM now, and I cannot get the RSAUM to shoot like I desire. I think personally, that shooting long heavies out of a short action, at least in the 7mm offerings might be part of my problem. Anyhow..

I want to rebarrel to a heavier barrel, currently a #4 Shilen prefit which is .685" at the tip.

I am looking for something in the sendero class (ends with .83") or perhaps a medium Palma ending .82" but taper leaves more metal along the way.

What I am having trouble getting my head around is the LENGTH of the shank. I am looking at Bartlein barels and the straight part of the shank varies from like 2" to 5"

Anyone know what the minimum shank LENGTH is to get the threads all cut?

My stock is a laminate that I can cut out to fit whatever taper I end up with. But I don't want to order some expensive barrel with a shank that is too short to be threaded for a Savage. (Planning to use SSS to cut threads and chamber once i have the barrel)

Hope this makes sense......

You might should ask Fred

Typically the commercial contours are 1.200" dia. at the breech, and must be turned down anyway for a 1.125 shank using a nut. I usually keep the cylindrical portion at 3" in length just so there is meat left for more threads in the event of a re-chamber.

Here is my leopard barrel, it's a large shank.
http://i78.photobucket.com/albums/j8...pszibzhsgt.jpg