I've carried a Browning HP in a custom made IWB that carries and conceals very easily. Loaded, I think the gun goes about 36 ounces. I feel this about the limit for me, weight-wise, for comfort.
I've carried my 5" Model 1911 which, loaded, is probably tipping the scale at 40 ounces or so. To support that weight, you really need to cinch up your belt to hold the gun in place and to keep your pants from drooping although that is now the popular style of dress in some circles.
Many of today's IWB holsters have unnecessary layers of leather which adds to thickness and discomfort. The less leather, the better. However, I'm not a fan of Mexican carry.