Don't open the threads up. It doesn't need it.
Pretty sure you mean magazine, not clip.
If it is a centerfeed action it is long enough for an Accurate Mag DBM setup. If you have a stagger feed action, you can lengthen the mag opening to mimic a centerfeed magazine.
Accurate Mag makes the DBM for the Savage Lapua. This uses the CIP length magazines. Problem with the magazines is that they are not compatible with RUM brass. They need to have the forward dimple removed (milled) for them to work.
I've built a couple 338 Edges on Savage actions. They are not well suited for this caliber as a repeater. Too much irreversible work, and hassle. They are very well suited as a single shot 338 Edge.