Nice! I'm really looking forward to taking the K31 hunting for the first time this year.
On paper, I think the Hornady 150 gr ballistic tips at 2900 fps will be my favorite for whitetail (branded Graf & Sons), although I also picked up some vintage Norma 180gr BTSPs at 2650 fps and new Hornady 165 gr BTSPs at 2730 fps. No doubt any of these would make short work of pigs, too.
The Swiss craftsmanship and the experience of working the straight bolt is too much fun. I'm keeping mine iron sights, however, to be more traditional. I do have a WWII 8mm Mauser Euro Sporter for times when I need a scope. It gives me extra satisfaction to hunt with something different!
Mauser Werke, Schmidt-Rubin, Colt, Walther, HK, Weatherby, Browning, Ruger, Beretta, Savage, Bushmaster, Marlin, Mossberg, Remington, PTR, Saiga, S&W, Sig Sauer....a few friends of mine