Ladies and gents, barring infirmity if you are struggling to pierce a mere 6mm (15oz) of bridle or plain veg with a diamond awl, you need to sharpen your awl. Stabbing it into glycerin soap every now and then helps too.
Consider the typical hand-stitched leather shoe (not a perfect example):
1 layer welting @ 2mm. 2 layers sole @ 6mm = 14mm , most of which is soling leather. If you've never handled it, soling leather is a very firm veg tan which has been compressed to be even firmer.
Consider further traces. These are the long straps which connect a horse's harness to the thing being drawn. They simply must not stretch or break. Proper old 'working' traces were made from three layers of heavy harness leather and stitched 2-4 rows along their full length (for which entire backs were needed).
So you see, hand stitching two layers of 8oz bridle leather to make a trouser belt isn't exactly an impossible task. No Dremels, drill presses or bloody Chicago screws needed.
Please don't think I'm trying to teach grandma to suck eggs; I'm a novice and there are those in this discussion that have much more experience than I.