i have been shooting the same 30-06s and 150gr psp corlokts for 30 years so i don' t have to shoot much.where i hunt,i have used a rangefinder to verify distances and the longest shot that i could take is 300yds.if you have ballistic charts,you can pretty much boresight and go to the range to sight in when you change guns or scopes.i found a great tool this year that really helps with new sightins when you don' t have a 300yd range handy.i downloaded " remington shoot" software which is free,and simply plug in the cal,type bullet and weight and pull up the graph trajectory to see the the two points that the bullet crosses.i sight in for 200yds so i can shoot dead on at about 30yds for a 200yd zero.when i get the chance to go to a range i shoot at 200yds and have found it to be very close to what i expect.