Hey,

I was just fondling my M1A and I realized the set screw for the rear sight was very loose, so loose in fact that when I turned the elevation knob the aperture didn't move. My question is this - do I bottom out the aperture and crank it back up 8-12 clicks to make a rough mechanical zero for 200 yards, as in the Garand, or is there a different setting? Should be the same as my M1, no?

I have an excuse to go to the range now and reset the dope on my rifle if nothing else Obviously I'm going to have to fine tune the rifle to figure out how many clicks it is exactly, but I need a starting point.

TIA.

start at 12, according to the army's FM 28-3

Mine is 13 clicks from the bottom (250 meter zero as per TM). This time when you zero the gun write down how many clicks from the bottom on a piece of tape and stick it under you fold up butt plate.

11 or 12 clicks from bottom is typically the 200 meter zero.  I have a kick ass standard model M1A with its own only flaw being the 200 meter zero is 15 clicks from bottom.  IOW, YMMV

It sounds like every rifle is a little different. I started with the 8-12 clicks at 100yrd like the book says and ended up with 3 clicks from bottom, 200yrds was 6 clicks from bottom using SA ball ammo.

It should be about 8-10 clicks from the bottom.