ORIGINAL: flounder33
Those spitfires have the boattail base so I don't think you are suppose to use the crush rib sabots with them. The Expanders should be straight down to the base so the crush ribs would be fine with them.
Best wishes,
Art
Barnes has just come out with a new Flat based TMZ, theboat tails don't shootwell in most Savages, but flat based bullets like the Origonal and MZ do. The bullet is called the Spit-fire T-EZ:
http://www.barnesbullets.com/products/coming-in-2008/new-spit-fire-t-ez%E2%84%A2/
Chap