Alvaro,
What sort of variations are you seeing from day to day?
33 and 41 fps difference in the average of two five-shot strings... First one a .270WCF loaded with modern H4831SC, and second one a 6,5x57R loaded with Vihta's N160. All four strings recorded at similar temperatures.
I know it is not much, but was wondering if positioning of the LR would be the cause.
You think such a difference is within the load randomness?
Alvaro