First of all, the object here is to not assume that everyone knows how to sight in their rifle. There are many new hunters and shooters every day. When we go to the rifle range, we all want to be able to at least hit the paper target. Whenever you buy a rifle or a new scope, at least have it bore sighted. This is the first step to properly getting the bullet to hit the paper.
Now you will have to decide at what distance you want it sighted in at. Most hunters use the 1 1/2" high at 100 yards, which will put you roughly at the zero at 200 yards. But with the 200 yard zero you will still have to estimate distances in unfamiliar terrain. A much better way is to sight your rifle in to give you the longest point-blank or dead-on hold that is possible without shooting too high at the mid-range point. With most high powered rifles and bullets, this means 3" high at 100 yards.
Unlike a target shooter who knows exactly how far his target is, you do not have to be too concerned about the distance, or hitting the center of the bulls eye on a target. Your concern is to hit the vitals of the game you are hunting. You do not have to be concerned if it is a little high at a short distance, so long as you can connect with the vital area. Unlike the target shooter will not have to hit exactly at your point of aim because the vitals on a bull elk are rather large.
The method that I prefer is simple. This method is to use a good sturdy rifle rest , one that can be used hands free, a sighting rest, and after your 3 shot group, look through the scope, place cross hairs on the bulls eye again, and now move cross hairs to the center of the 3 shot group. I have used this method with a one shot sight-in, and moved the cross hairs to meet the bullet hole. It is helpful if a friend adjusts the crosshairs while you watch through the scope.
Your cross hairs are now where your bullet is hitting. Now that you have it sighted in at 25 yards, move to a 100 yard target and repeat this procedure. Your goal should be for 3" high in a 1" or less grouping.
EXAMPLE FOR MOST HIGH POWERED RIFLES
Sighted in at 3" high at 100 yards, the bullet will hit about 3-4" high at 200 yards, almost dead on at 300-350 yards, and less than 10" inches low at 400 yards. This is a range that we all know as "pretty darned far".
Most weapons have capability out to 600 yards in the right hand with lots and lots of practice. Shoot your rifle at 400, and 500, and 600 yards to calculate your bullet drop at all 3 distances just in case.
To practice at 400-600 yards you should invest in a high quality Range Finder and a good rifle rest, you may need to go to a rifle range.
With the 3" high at the 100 yard sight in, you can hold dead center on the game out to 400 yards with no figuring at all. With a 100 yard zero you would be undershooting the vital area at less than 300 yards. This 3" high at 100 yards will bring out the cartridge's full potential. Use clear tape to stick your 400, 500 and 600 yard ‘bullet drop chart’ to your scope or rifle stock.