Just wanted to update this thread since I have solved the problem. Here's where I'm at:

Using the Hornady dies in my Hornady LNL press I have sized PMC, Fiocchi, and Winchester 223 brass with no issues. I've also sized PMC, LC, and IMI 5.56 brass with no problems.

I have tried everything I know of to size the Prvi Partizan 5.56 brass I have and can't get it to the correct length for proper headspacing. What seems to be happening is as it goes into the die it feels much tighter than the other brands of brass. Once the ram has been raised to the very top reversing it to extract the brass from the die is really tight almost as if it's going to stick. It will finally break loose with a pop which I'm really not comfortable with the force it requires to break it loose. Now I think what is happening is the shoulder and/or neck of the case is nearly sticking in the die and before the case breaks free of the die it is actually stretching back out a little causing it be slightly out of spec according to the headspace gauge. At least that's all I can come up with.

Anyway, I picked up a Lee full length sizing die and set it up tonight. Ran about 20 of the PPU cases through it and they run through the sizing die very smoothly and also check good in the headspace gauge. Still not sure why the Hornady die works perfectly fine with all the other brands of brass but not the PPU.

Either way, I'm just glad I have a way to size the PPU brass since I have about 3k rounds of it unfired. Thanks to all for the help. You folks have made the learning curve much easier!