Interestingly enough, I tried on a friend's pistol this weekend - and HK45 in an DeSantis IWB rig and guess what? It felt just fine. In fact, it was lighter than a Gov't Model - or was perceived by me - to be so.
Unless you have lower back issues or are overweight or use a rope for a belt there's no issues with carrying a full-sized pistol. Check your gear (i.e., belt and holster selections).
"Necessity is the plea of every infringement of human freedom. It is the argument of tyrants, it is the creed of slaves." ~ William Pitt, 1783