M1A Rear Sight Help

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Posted: 2/23/2020 10:53:17 PM EDT

So my M1A purchased back in October has a broken rear sight elevation knob, but I’ve been too lazy to replace it since my range has been soggy and I only shot it once at 25 yards, enough to get a rough BZO. Since it’s starting to warm up now, I need to find a replacement. What sort of a difference is there between a M14 knob and a Garand knob, other than meters/yards? Can I still set to BZO and then crank for distance without memorizing my clicks? If that’s the case maybe someone has one they would be willing to part with?
Thanks!

Posted: 2/23/2020 11:37:47 PM EDT

[#1]

The ONLY difference between the M1 and M14 rear sights are the M vs Yds thing. The can easily interchange and function exactly the same. Zero it at 25 yds to get it centered on paper, then set the sights for the 300 setting. Bottom out the elevation and then raise it between 9-12 clicks to start the process. Then confirm at 100-300 to confirm and adjust as necessary.

IIRC, my M1A was on at 10 and my M1 was on at 8 clicks.

Posted: 2/24/2020 9:42:40 AM EDT

[#2]

SA sold M1A's for years with M1 Garand rear sights on them. Mine came (1978 or so) with a set of lockbar M1 sights.

I left them on it for years before moving them to an old M1 a few years back and moving those sights to the M1A.

Posted: 2/24/2020 1:52:48 PM EDT

[#3]

Ok, so I can still zero at 275 yards/250 meters, and crank to a distance on the knob and it will still be close to correct at that distance even though its 30-06 vs .308?

Posted: 2/24/2020 2:49:11 PM EDT

[#4]

If you ignore the numbers on the elevation drum and just count clicks, you should have no issues.

Check your PM's.

Posted: 2/25/2020 5:52:40 PM EDT

[#5]

Another thing to check is the condition of the elevation serrations on the receiver. If the part that you are using for "zero to 500 yds" is worn down and getting flat, loosen the screw in the middle of the elevation knob, twist the knob half a turn and retighten the screw. As said already, count the clicks from "Full Down" for your required elevation.

Posted: 2/26/2020 7:15:54 PM EDT

[#6]

Quote History

Quoted:
Ok, so I can still zero at 275 yards/250 meters, and crank to a distance on the knob and it will still be close to correct at that distance even though its 30-06 vs .308?

View Quote

After I set my zero on the 300 yd setting, I can use the numbers like you are asking about. I've done it to the 800 yd target.

Posted: 2/28/2020 7:40:47 PM EDT

[#7]

They work out pretty much the same to something like 800yds. The M1 elevation knob is in yds. The M14 is in meters. But.... The M1 sight radius is bigger by about 10%.

So they work out the same. If you put either knob on an M1, it's going to line up close to yds. And if you put either on an M14, it's going to line up close to meters.

Posted: 2/29/2020 9:07:10 AM EDT

[#8]

The muzzle velocity and bullet weight for GI .30-06 and GI 7.62X51 are pretty similar.

Posted: 2/29/2020 9:17:04 AM EDT

[#9]

Thanks guys!

[ARCHIVED THREAD] - M1A Rear Sight Help

Armory » M1 / M14 / M1 Carbine

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