Must be that mine shrank in the cleaning and drying process.
Small primer .45 works, is nice if you also load 9mm (no need to change priming parts)... but you also get an IPSC PF drop of about 20. Slower ignition of powder.
Ammo that is otherwise identical and measures PF 170 with large primer is PF 151 with small primer, in the same gun.
Power Factor is a means of evaluating one's ammunition in certain action pistol sports to determine whether one is shooting major or minor power factor. Most serious competitors shoot major power factor, I think. IIRC, it is bullet weight times velocity (or something of this order) renders a number which will then determine which classification one will shoot in. HTHHelp here please, what is PF drop? I have seen some folks writing that there is no difference revealed in testing between LP and SP, but common sense urges me to believe there may be some difference - if not why would they have magnum primers?