6.5x284 With 120 Grainers

I am trying to load up some 120 grain Lapua bullets using RL19 for my 6.5x284.

Here is my question..

Nosler's site lists the following load data with RL19 and Lapua 120 grainers:

Starting load: 50.5
Max load: 54.5

Hornady's books lists the following for RL19 and Lapua 120 grainers

Starting load: 42.3
Max load: 48.1

Which one is correct? That is a huge range for a powder charged..

Thanks

Problem solved...

I had overlooked the fact that Hornady was using the Winchester cases and Nosler was using the Norma cases which explains the difference in charges.:frusty: