Does it matter about the burn rates of powders suited for a PCC like it does gas rifles? I know it makes a difference in rifles like the Garand with it's op rod but does it make a difference in an AR gas system?
I have a AR 15 PCC in 10mm and have these recommended powders on hand.

Action Pistol
Power Pistol
231
Unique
Universal
Titegroup

Is any one powder better suited for a 16" 10 mm
PCC?
Should I be worried about 'peak pressure' here or 'peak pressure' there or just load with what I have on hand and shoot?

Steve........