Mahogany for rifle stock?

Well, that came out pretty bloody good! Well done.

Rewarewa is very unstable having a massive sensitivity to moisture changes.
Tawa was used extensively for flooring , sarking and furniture , known as NZ Oak. I think iy would make good rifle stocks once properly milled and seasoned.
Podocarps all too soft including kauri. Kaik and silver pine soft. Kamahi is a hardwood and as for kowhai, might be worth a look. Puriri extremely stable and dense, but very heavy.. Lamination increases options of most of the above and could result in very attractive and strong stocks.

That looks nice, certainly different.