I thought about this very same type of carry for a BU gun. Even though my boots fit just fine my calves are a bit large so I don't believe anything larger than a very small auto or derringer would fit or be all that comfortable. It's not on my must have list yet but a thought just the same.
So some great info in here. I'm trying to find a similar type boot holster, and have been trying to find a simple solution. Any one actually buy something they use everyday? I think I'm going to have to make something to suit my needs here.
Thanks for the info.
I have tried boot carry with my Kahr PM40, using pocket holsters and an ankle holster worn fairly high. For short-term use, it works, but there are other deep-concealment methods I prefer. I found boot carry to be uncomfortable for more than a couple of hours. Good luck to the OP -- sounds like you may have an option that will work for you.