it used to be the 25yard zero it works well for m193 ball ammo from an AR it is about 6 inches high at 100 yards , 10 inches high at 200 yards and 6 inches high at 300 yards and 4 inches low at 400

so if you have a old AQT target the bell shaped ones and 100,200,300,400 yard qualification you bottom hold the target on the rapid fire stages 1,2,3 and at 400 you hold the head of the target

every round is different so you can get more from it if you adjust your sight in distance to match the arc and scope/sight over bore.

36 or 37 yards is an over simplification it mostly works on most common 308 and 223 like rounds

you look strait at the target your gun is at a slight angle to your optic or sight so that the bullet is angled up at firing it crosses the line of sight at distance A it reaches a maximum height over line of sight at B and it crosses back through the line of sight at C.

if we run this with my 308 round it is a 180gr bc .540 at average velocity of 2625fps my sight height over bore is 2 inches

my point A near zero is 35 yards my far zero is 200 yards so I could put a target at 35 and fire a round then aim on that bullet hole and adjust till I am cutting the same hole and I would be really close at 200 my far zero

my highest point is at 125 yards I am 2 inches high and 2 inches low at 235 this gives me a large usable point and shoot range it also lines up with points in my retical for shooting further

the mistake for me would be not verifying at 200 , what looks good up close is expanded at distance it is a stacking tolerance
I have seen people put up a 1 inch square target at 25 and hit it 3 times call it good and go to the long range at 25 yards a .224 bullet width is almost an MOA by the time you get the hole it basically is that could be an inch off at 100 , 2 at 200 and 4 at 400 so not terrible if you have no other range.
but I said they hit 3 times in the 1 inch square not that they stacked 3 rounds overlapping, they may have been 3/4 of an inch apart and still in that square or 3/4 inch at 25 yards = 3moa that is 3 inches off at 100 , 6 at 200 and 12 at 300 and 24 at 400.

so not confirming at 200 you can see could lead to a larger error from your near zero it is going to be hard to get the qualification score at 400 yards when you are 24 inches off on a 16 inch target

when you confirm your far zero and adjust as needed to bring you to point of aim point of impact , you can then go back to any point in between muzzle and far zero and be good left right unless you have a scope mount out of alignment with your barrel. your vertical will also be between your your muzzle and highest point of the arc

depending on the round your far zero may be 125 , 150 , 200 , 218 , 225 , 235 , 250 something like that

my far zero for 300 black out 110gr is 150 yards , it just isn't moving like 223 and 308

200 is what you see as the zero on the long range trajectory on most ammo boxes

200 or right around 200 has a lot going for it , at 200 it takes a wicked strong wind to effect 223 & 308 type bullets at those velocities.
unless you are above 20mph you don't even worry about wind at 200 , that doesn't mean you want to zero in the wind it is more likely to blow you off than the bullet.

200ish you can also see well enough your not fighting any optical issues with mirage

and if you center up a group at point of aim at 200 you can be sure it is going to be very close out further

you should shoot every distance you intend to take game at so if your going to shoot 350 , do it in practice best to be on every 50 yards and know your D.O.P.E data on personal equipment.

I guess that was maybe a little long worded for just saying on at 36 or 37 is good to go is an over simplification but if your in a place where that is the only range you have to shoot make sure your stacking bullets at 36-37 and it isn't for every round but 223/5.56 and 308/7.62 it is fairly close.

a 150gr from the 300 blackout is a near far zero of 38 and 125

near zeros tend to range from 25 to 42 yards it is the stacking of error that makes only a near zero not good when you get out further.

This.

In high intensity cartridges like the 7 RM, I sight in 2.5" high at 100, then for deer sized targets, hold lower third on the shoulder at 100, center shoulder for 200, upper third for 300, just above hair at 400, and 1' above the hair at 500. Beyond 500 I dial