Zeroing the M1 Garand Sights


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Bartholomew Roberts
May 17, 2004, 11:53 AM
I can't seem to find the answer to this in FM 23-5 or the manual that came with my CMP Garand; but what is the appropriate range to zero the irons with so that M2 ball matches the calibration on the sights?

I've currently got it zeroed at 100yds with the sight elevation set on the dash that is two clicks below the "2". Will this zero work at longer distances of say 500yds provided the appropriate elevation is dialed in?

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jem375
May 17, 2004, 12:29 PM
according to the info I wrote down some time ago it goes like this:

With a 100 yard zero:
100 to 200 yards........2 clicks
200 to 300 yards........3 more clicks
300 to 600 yards........12 more clicks

longtom4570
May 17, 2004, 11:23 PM
I seem to remember that you sight in at two hundred yards, then you would loosen the screw on the drum and turn the drum until the 200 is lined up on the line retighten the screw. then you can either turn the drum or hold under a little. If i rember right this is called Battle Sight Zero.

jem375
May 18, 2004, 12:18 AM
whoops...was thinking of something else...........

Trebor
May 18, 2004, 12:49 AM
In WWII, the Battle Sight Zero for the Garand shooting M2 ball was 300 yards. This was determined to allow for the greatest number of hits on a man sized target at varying ranges with the least amount of hold-over or hold-under required.

When you have your zero set, loosen the screw on the elevation knob and line up the correct range setting with the index line on the receiver.

cracked butt
May 18, 2004, 02:02 AM
Or even easier- sight in at 100, then turn the rear sight all the way down and count the clicks. Any time you want to reset the rifle to zero, turn the sight back down and count the clicks back up- it can be done in the dark.

Swampy
May 18, 2004, 07:12 AM
cracked butt has it right...

Murphy's Law proves that the M1 elevation drum will come loose at the worst possible moment (usually during the middle of a Match), leaving you with no way to know where your zero is.

No Highpower competitor worth the amount of powder it takes to blow his hat off depends on the markings on the M1 or M14 elevation drum. Competitors ALWAYS count clicks up from bottom for their zeros. That way if the drum comes loose all he has to do is tighten it back down, then re-apply the correct number of clicks up and he's back on dope.

Just my thoughts,
Swampy

Garands forever

TimRB
May 18, 2004, 09:40 AM
This is a very interesting discussion for me, since the longest range I have available is 100 yards. Anyway, am I correct in assuming that one could zero at some distance and, using the ballistic tables for M2 and a little math, figure out how many clicks up or down it would be at other ranges? I assume 1 MOA per click for a service rifle.

Tim

Swampy
May 18, 2004, 09:49 AM
TimRB,

You could do that, but why make it complicated......

For any load that will work Across the Course the following "Highpower Shooters" rule of thumb almost always works:

With a 100 yd zero to shoot at 200 yds, come up 1-2 MOA
For 300 yds, come up 2-3 MOA more
For 600 yds, come up 11 MOA more

This will keep you in the black 99% of the time and you get your sighters to fine tune the 10-X ring.

It's worked for me with both .223, .308, and 30-06.

Best,
Swampy

VG
May 18, 2004, 01:55 PM
This is a very interesting discussion for me, since the longest range I have available is 100 yards. Anyway, am I correct in assuming that one could zero at some distance and, using the ballistic tables for M2 and a little math, figure out how many clicks up or down it would be at other ranges? I assume 1 MOA per click for a service rifle.
Even changes in lighting conditions will change the amount of eleveation you require - hence "Light up, sight up." I put a new sock set on my rifle and the zero changed from 3 to 0 to 6 clicks over the space of a month.

I vote with Swampy - it's OK if you want to zero to get in the ballpark, but count the number of clicks up from bottom, and record the value.

swampbuk
January 11, 2012, 04:00 PM
When I was in the Army we had M1 's
Its been a few years ago but our battle sight zero was a 4 inch square we shot at ( I though 75 yards) . You aimed at the bottom and hit the top, then you were set on half man targets to 600 yards. at 600 you aimed at the head

P-32
January 11, 2012, 04:28 PM
With a 100 yd zero to shoot at 200 yds, come up 1-2 MOA
For 300 yds, come up 2-3 MOA more
For 600 yds, come up 11 MOA more

I go even further than this. At each time I get ready to fire from a different distance I count from the bottom. I have recorded the number of clicks of elevation I need to put me on paper for my sighterís I can obtain this information while getting ready to fire in the prep time. The reason I always come up from the bottom is there is no question if I put the right dope on. I also mark the sights with red paint which tells me if the sights are at the bottom and the wind age knob centered. 1/4 MOA AR sights get a lot of counting coming up for 600. (64) But I know Iím going to be on.

Double Vision
January 11, 2012, 05:31 PM
This is a good read, thanks for the info.

lencac
January 11, 2012, 06:00 PM
If the front and rear sights are 28 inches apart, each .001 in. increase in elevation of the rear sight will raise the point of impact at 100 yrds. 1/8 in.
So elevating the rear sight .008 in will raise point of impact 1 inch at 100 yrds.
Formula: 3600 inches in 100 yrds. divided by the distance, in inches between the front and rear sight. That # you multiply by the amount, in thousandths of an inch that the rear sight elevates. The answer will be the amount of increase of impact at 100 yrds.
With that and knowing the velocity and a ballistics calculator a person can on the bench calculate the resultant changes needed for a given range.
All it requires is a caliper, a tape measure, a chronagraph, a calculator and a ballistics calculator.
Simple;)

jr_roosa
January 11, 2012, 06:27 PM
The real trick is tightening the screw. Once you get it to where your 100yd setting (5 clicks on my rifle) lines up with the 100yd line, you have to run the sight all the way up to be able to tighten the screw enough so it doesn't come loose within ten shots. Guess how I learned that lesson.

J.

P-32
January 12, 2012, 03:14 AM
lencac, Would it not be a little easier to know how many clicks of elevation you need on your rifle for a known distance? Waste too much time trying to figure out how to do the math.:D

lencac
January 12, 2012, 01:24 PM
P-32, I never do anything the easy way ;)
Although I do use that method to familiarize myself with new rifles or loads. It kind of gives me a basic baseline to start with.
And in actuality it does differ some but it's still amazes me how close it actually is on many rifles.
It's just a useful method is consider.

P-32
January 12, 2012, 07:19 PM
You'll learn. ;)

30Cal
January 12, 2012, 10:42 PM
I always count the clicks. ALWAYS. And write it down.

If you want to calibrate the drum at 100yds, center your group on the target. The count the clicks down. You're now going to use the bottom stop to hold the aperture in place while we fiddle with the elevation drum. Loosen the screw on the elevation knob. Click it in the down direction til you reach the "2" mark. Then click (again, in the down direction) the number of clicks you need for zero. Then two more clicks. Tighten the elevation knob screw.

Basically, your 100yd setting will be 2 clicks down from the "2"

henschman
January 12, 2012, 11:13 PM
The number of clicks between each yardage marking on the drum is the trajectory for M2 ball. It's different for my M1A since I know it in Meters instead of yards, but I know that for M80 ball, my 100m zero is 8 clicks up from bottom, and my come-ups starting from 100m and going up in 100m increments are 3,3,4,4,5,5,6,8,8, which gets me out to 1000m. But like others have said, don't count on the markings. Memorize them. For that matter, don't count on the factory come-ups. They are usually really close, but it is best to hit a known distance range and verify your come-ups for each distance the hard way, and WRITE EVERYTHING DOWN.

BTW a 25m zero equals a 200m zero. BSZ for the M1 is a 275 yard zero, which is 2 clicks up from 200. Your front sight is the width of a man-sized target at 275m. So if the guy is as wide or wider than your front sight, just give him the old 6 o'clock hold and squeeze. If he's much smaller than the front sight, you'll have to know your come-ups or your hold-offs.

Have fun!

BigSteve57
January 13, 2012, 10:43 AM
Or even easier- sight in at 100, then turn the rear sight all the way down and count the clicks. Any time you want to reset the rifle to zero, turn the sight back down and count the clicks back up- it can be done in the dark.
This is EXACTLY the advice they gave me when I attended a M1 Garand clinic shortly after I purchased my Garand. It's great advice. Memorize that count!!!

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