What would you consider acceptable reload bullet length variance to be measured at the ojive?

In decimals of an inch. .0000

It depends on the bullet. What bullet are we talking about?

A hollow point bullet from Berger or Sierra will vary anywhere from .005" to .011" when you measure multiple bullets at the tip. But measure the ogive, and they are spot on. If you are loading ammo and seating bullets, you shouldn't have hardly any variance, less than .002 or less. If you are getting a variance, it's most likely due to the brass. The brass is not consistent, case prep was not done consistently, various brand cases, etc.

^^^What Chad said^^^

I loaded up a 50 batch of Sierra Gameking btsp for my 7 RM last night to hunt with. Loaded them at .020 jump. They all measured 2.731 spot on to the ogive. Measuring Cartridge overall length they ranged from 3.231-3.239. The soft lead tip is where the variation in length came from. It will make absolutely no difference in how they shoot.

I probably should also mention that the fitting of seating stem to bullet can cause variation in length. If it is engraving the projectiles, seating depth will be wonky.

Bearing surface length is the number you’re looking for.