Hoser-

Looks like you made it onto this site - Welcome!

First thing - the rifle (soup-to-nuts) is regulated by the gunbuilder.
You load ammunition to shoot to the regulated sights.
A properly developed load in a properly regulated rifle will put the groups together, barrel Center-To-Center distance apart from the muzzle to the dirt, wherever they fall.

SO - A proper load is a proper load, within the muzzle flash on out to max range for your shooting abilities.

Does that make sense?
Hope so.
If not ask questions.

I don't have any suggestions (based on personal experience) for you for a manufacturer of ammunition.
I've done all my own manufacturing and load development.
For what you're looking to do it should be cake.

Cheers
Tinker