Try measuring just a bullet in the hornady chamber all system.
With the appropriate caliber bushing on one end of the caliper, just measure any given brand of bullet to compare how consistant the ogives are.
I found that berger bullets normally measure +-.0015" or less varience.
Nosler ballistic tip/accubonds are often +-.002" or better.
Sierras are "normally" close to the same as noslers.
Hornady are close in varience as sierras.
Speer can vary as much as +- .010"! Wow!
I attribute(suspect) that speer doesnt have that bad of quality control. I think that Speer may "common process" multiple bullet making presses Together in hoppers. Each bullet press producing its own consistant bullet dimensions. Mix all the bullets from each press and you have inconsistant ogives!
That alone could produce the issues with varying OAL's.
I have done comparisons like this in the past many times. Manufacturing processes change, so measure the bullets you have to see if rules of thumb still holds water.
Berger has figured out long ago to package bullets from a single press to enhance consistancy. Lot numbers will even boost thier ability to trace problems reported to them. Directly to the individual press probably.
Hope this info/perspective helps in some way.