Try 185g Berger BT (now called Juggernaught). Something like 42 g of Varget will work just fine. Used it out of my TRG 20" and it worked real nice. Use the same combo out of my PGW Coyote only this week and shot in the .3's at 400y ( don't worry - it will get you to1000.)
Now for some advice: I know 20" tubes will get it done but it will be an easier road with a longer barrel.
Now for some advice: I know 20" tubes will get it done but it will be an easier road with a longer barrel.