Senior MTF Member
Join Date: Aug 2010
Location: Butler County, Pennsylvania
Re: Holding your zero past what you sighted it in for.
I generally sight all my high power rifles in at 1 inch high at 200 yards. With that, you can hold dead on a deer sized from point blank range out to 300 yards and not have to adjust your hold. That works well for Western Pa, 300 yards is an extemely long shot around here, out west, it's another story. I shoot only reloads, and most reloading manuals have very good trajectory charts in them. Hornady is my favorite. If you know your ammunitions velocity and the grain weight of your bullet you can find the best "zero" for your rifle. With a .270 140 grain boattail traveling around 2900 fps for example, 1 inch high at 200 yards puts you roughly 3 1/2 inches low at 300 yards, and around 2 inches high at 100 yards. Well within the kill zone if your hold was dead center of the chest. This will vary between bullet types and loads. Best to try your rifle out with the ammunition you'll be shooting and see exactly where you are. Your .300 will be a little different, but should be in the ballpark.
Some of my tractors pics are in the link below, click the picture.