I have a box full of belts - leather and nylon - that I bought over the last 30 years, looking for the best belt for wearing casually and in suits for special occasions that also comfortably carried my full size pistols and four spare magazines. I have regular leather belts and shark skin and elephant skin. I have belts from The Belt Man and other leather makers as well nylon belts from 5.11. The only one that fit the bill is my 5.11 Apex Gunner's Belt. It is B10 coated webbing that is the same thickness as a regular dress belt, but, has tensile strength of 1,500 lbs. It easily and comfortably carries my full size steel pistols and four spare magazines. I purchased a couple, in case they were to wear out. I'm still wearing the original one that I bought about 10 years ago. I wore this one for 3 years at work on/off duty before I retired. And continue to wear it in retirement.
All of the leather and nylon belts that I wore were good for about 5 - 7 years and both would fray, deform, and mildew (from sweat during hot, humid summers). My 5.11 Apex Gunner's Belt is still like new, well almost. Just a slight bend in the belt after conforming to my waist with the weight of a pistol and four magazines after years of usage. I actually think this belt will outlast me.
Unfortunately for those that did not buy one, it appears that 5.11 discontinued them. I also noticed a similar belt called the Liger belt made by Maxpedition. But, it looks like Maxpedition discontinued that belt as well. If you search around, you can sometimes find a 5.11 Apex Gunner's belt that is new, old stock. Then it's a matter of finding one in your size.
5.11 Apex Gunner's Belt, the only belt that I wear and have worn for the last 10 years and still going strong. The price was $60 and worth every penny.