Have any of you guys tried the PowerPunch 460's?

I was just reading this over and remembered I had brought my calipers home from work to measure the Bullshops. They were a consistent 0.5040" and I do mean consistent. Every one, all the way around, no matter where it was measured. No wonder they shoot so good.

Then I thought about measuring the conicals (PowerPunch 460's) that came with the Ultra Mags. Much to my surprise, right on the package it says .50 (503) caliber. Hmmmm, that's interesting. I measured and they were for the most part 0.5030 but that was on the front rib and back rib only. The inner 3 ribs are more like 0.500" or a little less, but not very consistent. The front and back ribs were not near as consistant as the Bullshop bullets either.

So, based on my experience with the slip fit of the Bullshop bullets (504's) in the Ultra Mag, why in the world would they supply 503's with the gun. I haven't tried it, but I would imagine they would just slide freely in and out of the barrel and I can't believe they would be accurate. Am I missing something???