I think the advantage to the large shank is if you choose to stay with the barrel nut (as Savage has), it gives you thicker chamber walls on the portion that extends beyond the receiver. It goes from 1 1/16" to 1 1/8" (small shank compared to large shank) which may not sound like much, but an extra 1/16" of steel adds a good bit of strength. The dimensions of their Lapua actions are the same as the other long actions. However, due to a different heat treatment process, and smaller ejection port, they are stronger than the standard long action. I'm glad your Lapua gave you good service. I recall reading an in depth discussion from Sharpshooter years ago about chambering the Lapua on the small shank in a standard action and his results were not so favorable. IIRC it included, chamber swelling upon firing and lug setback.