nocturnal, check out www.grafs.com
Apparently, they convinced Hornady to load ammo for them under the Graf and Sons name, but it is identical to the 3 loads Hornady has sold---150, 165 and 168 gr. Apparently the 150 gr are highly sought after and I've only been able to find them at this website. Having them with ballistic tips is a (very nice) bonus!
It seems GP11 was mostly made in 1979 who knows how much of it is left. I'm well stocked, although I may get more before long. It is the standard for our K31s and cool piece of history...
Mauser Werke, Schmidt-Rubin, Remington, Colt, H&K, Weatherby, Browning, Ruger, Savage, Marlin, Mossberg, Saiga, S&W, Sig Sauer....a few friends of mine