It's pretty much just the idividual rifle in cases like this. I found a long time ago that the variation in how a particular rifle will shoot one type factory ammo in comparison to another can be stunningly different. And sometimes there appears to be no rhyme or reason to it either. I've got one rifle (a Browning A-bolt in 7mm-08) that I havetest fired withjust about every type of factory ammo out there. What does itgroup best? Cheap ass Winchester power points.
I have never had a major problem with a rifle and Cor-Lokts. Had some guns that really liked them and some that were justokay with them but I can't recall one that grouped over 1.5 inches with them. I have a buddy who shoots the 120 gr Cor-Lokt out of his 25-06 and his rifle will shoot1 inch 3 shot groups with them.
I don't like Game Kings since a friend showed me a bottle of Game king jackets that he had recovered from game.
I always found them to be a very accurate bullet but one of the most frangible lead tip bullets out there. I think they have a thinner jacket than most cup and core type bullets. I shotthe Federal Gamekingsfor a while in my 25-06. They would group under 1 inch all day from my Tikka but they came apart like a hand grenade in deer. I use 117 gr Hornady Interlocks in it now. I really like the Interlocks for a standard lead tip bullet.