So the best way to line everything up short of truing it on the range is just to use a ballistic calculator to get your starting point. What I mean by that is take the drops in the reticle:

300m - 0.8 mils

400m - 1.8 mils

500m - 3 mils

600m - 4.5 mils

Now you take the load you plan to shoot, preferably after you've run it out of the gun you plan to mount the optic on over a chronograph (there can be a shitload of variation for the same round out of different barrels even with ammo from the same lot, you'd be surprised). You take the ballistic coefficient of the projectile, combine it with the speed, the atmospherics + elevation of the area you're in and now run it through JBM.

Since you mentioned 55 grain (presumably m193 ball, btw this choice is going to suck because of how bad the BC is but we can probably even get this to work reasonably ok, about to find out because I'm doing this as I write the post) Now we'll plug it in and see what the results are:

1.54 assumed mount height for a 2.74 height over bore, m193 assuming 2990 FPS out of a 16"

For a 100m zero with 193 ball at sea level today's temps in my area you end up with 1.3, 2.6, 4.2 and 6.5 mils respectively.

Now we adjust the parameters of the zero to determine what's going to be most effective for us. Keep in mind with a lightweight, low BC projectile like M193 trying to make hits out to 600 is not exactly going to make a ton of a sense so you may as well throw that one out the window.

To keep this simple we can either: adjust mount height (if you have different mounts, i.e. a 1.93 will have a different arc that a 1.54) adjust zero offset (i.e. zero 1" high, how you zero the SVPS atacr for example), or adjust zero distance.

First let's just adjust our zero distance from 100m to 36m and see what we get:

0.5, 1.8, 3.4

What does this mean? Basically you'll be within 6-8 inches at any of the distances the BDC is at out to 500, a little high at 300, dead on at 400 and a little low at 500. For combat accuracy with a BDC I could live with this using a suboptimal projectile.

Another approach would be to zero it at your maximum point blank range, what this means is that you can just hold straight on with the reticle for combat accuracy out to something like 300 meters and then hold over. With the parameters we already punched in the maximum point blank zero is 265m and that gets us:

300m -0.3

400m -1.6

500m - 3.2

This is probably closer to what I would do if I had to run m193, you're mostly going to be holding dead on for center mass and then your holds and 400 and 500 are so close that you really don't need to hold any different. For IPSC steel or something like that this is more than adequate and realistically you aren't making precision shots at distance with an LPVO, let alone with ball ammo.

Hope this was helpful!