When I had a boss equipped rifle the sweet spots were not where they were supposed to be even for the loads given.Trial and error was the only way to find out where the sweet spots are.I discovered that I spent more time and ammunition adjusting the boss than I do in developing handloads for a rifle and the results are no better with the boss than with handloads and no boss.For that reason and the extra noise and muzzle blast the boss muzzlebrake provides,and the reduced velocity of the shorter boss equipped barrel, I sold the gun.