Bruno,
if you neck size, you are "go" for one rifle, from which you got the brass.
You will increase the life of the case at least by 40-50% just neck sizing.
Also, you may improve accuracy just doing the neck.
Reloading is a complex activity and 2-3 grain bellow the max charge is hard to establish, not knowing what is the max OAL to the ogive. Having that information we decide how far we want to be from the ogive and what is max safe charge for that caliber.
You know that the ogive is a part of the bullet, don't you?