29 just in case..
I shoot 44spl+p using Magnum brass.. no where near full house 44Mag..just a little more zip..
I have a 629-4 4" and this is basically what I shoot out of mine.
I really like it.
My other 44 is a 696 no dash and shoot standard pressure loads through it.
If you are fond of the 24's weight and balance, you may look for a mountain gun. 29 or 629. I think it would give you a very similar if not exact feel of of the 4" 24 and while a little hard to find, much easier to locate than a 4" 24-3. I spent a lot of time looking for a good 24-3 4" and finally caved in and bought the 629 and 696.