I'm getting ready to order another dial for my VX3 4.5-14x40 CDS. For the possibility of a shot out to 4-500 yds. should I go w/ a dial zeroed at 100, 200, or 300 yds.? The majority of shots will be inside 200 but what's the most popular zero w/ the CDS scopes?

100

Unless you are a long range "shooter" (1,000 yards).

If you're shooting a ~3,000fps bottleneck rifle round, 200. If you're shooting a .45-70, then 100. For most standard and magnum rifle cartridges, you're looking at a ~250-275yrd MPBR for a 200-230yrd zero. Shorter gives a smaller variance, longer gives larger, and if you're dialing every shot, none of this matters - but if you only want to dial 300-500yrds and hold dead on or slight hold over/under without dialing from 0-275, get them at 200.

To be honest, it's all arbitrary anyway - your zero doesn't matter, just need to match the turret to the range and it'll be zeroed for that given range.

Thanks guys, it's going on a .257 Wby Mag. wouldn't mind plinking to 600 yds. if it (I) can but hunting 4-500 yds. Also, how the heck do I figure out the sight height info to send to Leupold?

Measure the distance between the center of the barrel and the center of the scope.

I have a 6.5 that shoots a bullet at only about 2650 fps. The CDS dial on that rifle is zero at 100 yard. It is good for over 550 yard. I like it. A 257 Weatherby would be good for further if zero at 100.

What Leupold needs to know is;

Caliber, cartridge (Specs if hand rolled), barrel length, twist rate, etc.

The difficulty lies in the atmospheric conditions you will be using that gun in ???

the more you move the dial the more room for error, I always sight my long range rigs in at 300. you'll be less than 2.5" high at 100, sight in at 300, hold lower third of the shoulder to 200, dead on at 300, just under the hairline at 400 when you don't have time to dial.
RR