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Old March 14, 2020, 09:22 PM   #1
baddarryl
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Sighting My Garand

Hi guys. I still don’t know my Garand that well, but I am getting there. Today I took it out to zero at 100 for a CMP match coming up. I had previously sighted it at 25m and found I had to come down 10 clicks for 100. My question is if the rifle is zeroed at 100 where do I put the drum markings to correspond to that so I can later find my clicks for multiples of yards. I will likely mostly use this rifle at CMP and possibly Appleseed KD. But I think I prefer a 100 zero for the CMP as I may do that more than anything, but this will be my first match.

Also for some reason when I first got it I had to move the front sight. Now my witness marks are off by a few when it’s shooting straight
Did I move it too much maybe? Thanks.
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Old March 15, 2020, 07:40 AM   #2
David R
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If its shooting straight, then yo got it.

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Old March 15, 2020, 09:02 AM   #3
hagar
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A 25 yard zero is about the same as a 300 yard zero, so about 9 1/2 moa clicks sounds right. Don't worry about the drum markings, count the clicks up for every distance and you will not have to worry about it.
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Old March 15, 2020, 10:34 AM   #4
Wyosmith
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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.
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Old March 15, 2020, 03:39 PM   #5
Bart B.
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Darryl, if your Garand needs 4 clicks up from the bottom to zero elevation for 100 yards, loosen the windage lock screw then reset the elevation knob to 2 clicks below the 200 yard mark to make that happen. Tighten the lock screw.

Other range elevation zeros will be close to the knob scale number marks, but seldom exact. Windage zeros often have a 1 MOA spread across all shooting positions.

Done this with several Garands and never modified the front sight in any way. Well covered in this link:

https://www.fulton-armory.com/faqs/M...ighting_in.htm

Wyosmith, never seen nor heard of your method to set sight elevation to some standard. It doesn't allow for any variables across all types and lots of ammo. Nor different rifle critical parts replacement, for that matter. What's your source for this method? Just curious......

That's a bad way for service rifles used in combat environments. What if someone else had to use that rifle in the field and couldn't set the sight low enough to get a 100 yard zero? Everyone doesn't use the same sight windage and elevation settings for a zero at different ranges with the same rifle and ammo.

Wasn't the caliber .30 M1 cartridge with a 174.5 grain bullet leaving about 2647 fps the one most used for the original mass produced M1 rifles?

What Field Manual has such instructions you mention? Were service personnel issued a file to lower front sight height?

I've never seen any military spec for military 30 caliber 150 grain bullets leaving 2850 fps out the muzzle.

Last edited by Bart B.; March 16, 2020 at 10:36 AM.
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