Well I know about most of those options. I was curious if anyone offered a custom action that would fit the footprint of the xp100 action. Im wanting to build a center grip in possibly 7wsm,7saum or 6.5 saum. But xp100s are getting pretty rare and hard to find. So it im building a custom might as well go with a custom action.
I did just pick up two xps though and one might be a good candidate for a build as it looks like its kinda been tinkered with.