I coupe of clarifying questions:
1. Am I correct in assuming that the "Remington factory 125 gr SJC HP" ammo is loaded in the factory, and all other ammo in your tests was loaded by you with your die set-up?
2. Are your 158 gr SWCs swaged lead, cast lead, plated, jacketed cup-and-core (e.g., Speers old design), or "jacketed" with some sort of thick plating (e.g., "jacket bonded to core one molecule at at time") like Speer's new unicor/Gold Dot bullets?