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Wyosmith · March 15, 2020, 10:34 AM

The best way to do it is to set the rear sight in the center of the scale and zero for windage by loosening the front sight with the larger Allen screw on the rear of it, and moving the front sight in the direction of the bullet hit until it is able to cut a vertical line in half on your target at 25 yards. Then tighten the sight screw up.

Next, loosen the screw on the elevation drum and counter turn it to set the elevation for the 100 yard mark (just under the marked 200 yard stamping on the drum) and re-tighten it. The gun will now shoot low. Use a small grinder of good file to then cut off the front sight to bring it up and do this zeroing at 100 yards. Some have to be ground instead of filed because some are quite hard. An easy way to do this is to fire a few shots at 100 yards and mark the center of the groups, Now come up about 4 clicks and fire another group and see how far 4 clicks moves the impact. You than then measure the height of the aperture at bottom and again at 4 clicks up, and know how much difference it makes with YOUR rifle. That way you can mathematically figure how much metal to remove from the front, and get very close on the first cutting. Going down (for example) .030" in the front is exactly the same as coming up the same .030" in the rear.Cut about .010" less then your math says, ---- so you can then come up just a bit at a time for the last adjustments, but knowing how much to "rough off" the 1st time saves you a lot of time and ammo.

The Army and Marines of course never did this with all the M-1s made going through WW2 and Korea, but this is the system J.C. Garand designed for his creation and it works perfect if you do it this way. I have done this with probably 40-50 M1s over my carrier as a gunsmith, and it's a perfect system for setting the rear sights to calibrate exactly. When done you are exactly zeroed at 100 yards when the rear sight is at bottom dead center.

Once done the rear sight can be set to center and it will shoot center at all ranges in Zero Wind conditions, and you can dial the rear sight to any distance on the drum, and it will shoot to that point of aim with M2 Ball ammo or it's equivalent (150 grain flat base bullet at 2850 MV.)

March 15, 2020, 10:34 AM	#4
Wyosmith Senior Member Join Date: December 29, 2010 Location: Shoshoni Wyoming Posts: 2,713	The best way to do it is to set the rear sight in the center of the scale and zero for windage by loosening the front sight with the larger Allen screw on the rear of it, and moving the front sight in the direction of the bullet hit until it is able to cut a vertical line in half on your target at 25 yards. Then tighten the sight screw up. Next, loosen the screw on the elevation drum and counter turn it to set the elevation for the 100 yard mark (just under the marked 200 yard stamping on the drum) and re-tighten it. The gun will now shoot low. Use a small grinder of good file to then cut off the front sight to bring it up and do this zeroing at 100 yards. Some have to be ground instead of filed because some are quite hard. An easy way to do this is to fire a few shots at 100 yards and mark the center of the groups, Now come up about 4 clicks and fire another group and see how far 4 clicks moves the impact. You than then measure the height of the aperture at bottom and again at 4 clicks up, and know how much difference it makes with YOUR rifle. That way you can mathematically figure how much metal to remove from the front, and get very close on the first cutting. Going down (for example) .030" in the front is exactly the same as coming up the same .030" in the rear.Cut about .010" less then your math says, ---- so you can then come up just a bit at a time for the last adjustments, but knowing how much to "rough off" the 1st time saves you a lot of time and ammo. The Army and Marines of course never did this with all the M-1s made going through WW2 and Korea, but this is the system J.C. Garand designed for his creation and it works perfect if you do it this way. I have done this with probably 40-50 M1s over my carrier as a gunsmith, and it's a perfect system for setting the rear sights to calibrate exactly. When done you are exactly zeroed at 100 yards when the rear sight is at bottom dead center. Once done the rear sight can be set to center and it will shoot center at all ranges in Zero Wind conditions, and you can dial the rear sight to any distance on the drum, and it will shoot to that point of aim with M2 Ball ammo or it's equivalent (150 grain flat base bullet at 2850 MV.) Last edited by Wyosmith; March 15, 2020 at 10:55 AM.