RE: Question about barrel length in 7 mag.
encore barrels need a little more detail in correct head space measurements to shoot to there fullest potential. you need to know barrel to frame gap and resize your cases so they protrude .001 less than that distance. you can measure barrel to frame gap with feeler gauges. case protrusion can be measured with a depth mike or by sizing cases till a piece of aluminum foil slips out between the case head and cylinder face on a closed chamber.
a loose barrel hinge pin that allows wiggle when your action is open also can effect group size as well. good luck in your quest for accuracy.