I've previously purchased (2) paris of Propper's Summerweight Tactical Shorts in size 32 waist.
One pair came in sized correctly, though a little snug, while the other came in very tight and had to be returned.
In short, from my experience with Propper's shorts, these tend to come undersized.
CogentCThe sizing depends largely on which "fit" the shorts come in. For example, the Summerweight shorts are "athletic fit" so they run a little slimmer. The EdgeTec shorts are "classic fit" so they have a bit more room and run a little bigger. Not a lot bigger, but enough that sizing up is often too much.