|
"...just pick one load to start with..." Start with just one powder. Best one is the 'Accuracy load' for a specific bullet weight. Said bullet weight (really no need to worry about the BC' etc. for a hunting load.) selected according to calibre and intended use of the rifle. Usually a 130 or 140 for a .270. Loaded to the max OAL given in your manual.
Forget the off-the-lands stuff altogether until you've worked up a load. That's a 100%, trial and error(every chamber is different and every rifle will prefer a different distance off the lands. There is no average or set distance at all.), load tweaking technique that is unnecessary. It's an 'If you feel like it' thing after finding the most accurate load.
Beginning with the starting load given in your manual, load 5 rounds only(A mag load if your rifle holds less than 5). Go up by half a grain of powder, loading 5(or a mag load) of each keeping them separate until you get to the max load in your manual.
Then go shooting. Shoot at 100 yards, for group only, slowly and deliberately off a solid bench rest.
Change targets between strings of 5(or a mag load) and allow time for the barrel to cool.
When you find the best group, sight in high at 100.(how high depends on the load and bullet weight. A 130 at 2900ish FPS MV gets sighted in 1.4" high at 100.) That'll put you on target out to about 300 yards with no hold over with a .30-06/.308 and the like.
500 yards is to far for a .270. A typical 130 grain SP sighted in at 200 will drop 39.2" at 500. A 140 drops 39.9" at 500. With barely enough remaining energy out of either weight.
|