I have a 6mm PDK that is very similar. It is a 6.8 spc based cartridge that is necked down with the shoulder moved forward. I use it for deer and groundhogs. I have loaded 100 grain sierra gamekings and 85 grain TSX barnes for deer and 63 grain varmint grenades for groundhogs. I am shooting these from a Krieger barrel with 1in7.5 twist IIRC. I have not gotten the TSX bullets to shoot as tight out of this gun. Accuracy is certainly acceptable for deer hunting (1.5" @ 125 yds) but the other bullets that I mentioned will shoot around an inch at that range. I have to fire form and, while being interesting is somewhat of a drag after a while. I have to look at my notes but I remember that Varget and H4895 have given good results with both bullets. both of these cartridges have a nice balance of case capacity to caliber. I don't know what your intended use will be but it will be a very fun and capable round for target, varmint and even deer when you keep the range reasonable.
