RE: 777 powder
Couple of things to add: First I am not a fan of 777 due to the hard fouling ("crud ring") that if forms in my stainless Omega. Next; if you try to shoot maximum loads with Powerbelts they may not be giving you the best accuracy. Most find 80 to 100 grains is about all they can take in most rifles. I get good results with Pyrodex loose and Powerbelts or with American Pioneer Powder and Powerbelts or Black Mag3 (which is my powder of choice now) and Powerbelts. All of these loads are 100gr. or less of powder.