Here's an old post on how to set up and use the M1 Rifle sights, for both the combat (hunting) method and the Target shooters method.
BOTH can be used once you set the sights up. In other words, you can use the battle sight or the Target sight method as you want.
When hunting or plinking use the battle sight method, on the target range use the Target shooters method.
There are various methods of setting the sight so the markings agree with the range but the simple method is this.....
Raise the rear sight 8 to 10 clicks and shoot at 100 yards, adjusting the sight to get into the center of the target.
Note that you need to use point of aim-point of impact aiming. In other words, the bullets hit where the sights are aimed.
Aim at the center of the target and the bullets should hit the center after the sights are adjusted.
DO NOT use the target shooters 6:00 O'clock hold where you aim at the bottom of the black and the bullets hit up in the center. If you do that the sights will be off.
With the rifle sighted in and the bullets hitting the center, grip the elevation knob tightly with WELL PADDED pliers so it won't turn and unscrew the elevation knob screw.
It's a captive screw and won't come out.
Pull out on the elevation drum then turn it so the 100 yard mark lines up with the index mark on the receiver.
The 100 yard mark is the line under the "2" marking, which is 200 yards.
Push the drum in and gripping the drum with WELL PADDED pliers so it won't move, tighten the screw down snugly.
Check the setting by lowering the sight and then turn it back up so the 100 yard mark aligns with the receiver index mark.
Shoot the rifle to insure it's on target.
Note that this only works with USGI spec ammo. Heavier or lighter bullets or ammo loaded with non-GI spec powder will not target correctly.
Also note; this is the combat or hunting method of using the sight. It won't be perfectly exact for all ranges, but will be close enough for combat or hunting.
There is a "correct" method of doing this without using padded pliers, but this one is easier AS LONG AS YOU USE WELL PADDED PLIERS so you don't damage the elevation drum.
For full details see the US Field Manuals on the M1 Rifle.
You can get online copies on this site....Note the info at the page top on what username and password to use to get in.
This site has the users manuals and the Ordnance manuals........
Biggerhammer.net - Miscellaneous Firearms Technical and Training Manuals
With the elevation drum set, you can shoot at any range by turning the elevation drum to that range and with USGI spec ammo you'll be "Minute of man".
Happily, you can also still use the target shooters sight method.
Lower the sight down to the bottom and raise it about 8 to 10 clicks and shoot at a 100 yard Official target.
As you adjust the sight up or down keep track of how many clicks up or down.
Once your sighted in, just lower the sight, counting the clicks until it bottoms out.
Write that number down somewhere.
Now to get on an official target at 100 yards all you have to do is raise the sight that number of clicks.
Repeat this for every range you want to shoot at and write the number of clicks up for each range.
To shoot at any range you've done this for, just raise the sight that many clicks and shoot.
Note; This only works with official targets for a specific range. If you shoot a 200 yard official target set at 100 yards you'd be off.
Also note, the target shooters method is usually used with a 6:00 O'clock hold. That is you aim the sights down at the bottom of the black and the rifle puts the rounds up into the center.
The target shooters 6:00 O'clock aim is used because it's easier to align the sights with the target.
