Like mentioned in the title, just for fun. And to get some action on the forum!
A video where I chop out a mortise. I follow more or less the method I gleaned from Paul Sellers. First from one end of the mortise all the way to the other end, going deeper en deeper with every step, bevel leading, riding the bevel so to speak. I set the chisel down in the vicinity of the next stroke and then wiggle until it is perfectly positioned. This method creates a ramp on both ends of the mortise. These I remove, chopping straight down with the bevel facing to the middle. Usually I get 3.5 cm depth on a 1/4" tenon with a bit of a bulge in the middle. At last removing the very last bits on either end of the mortise, also straight down bevel facing to the middle.
I'm not very quick but I manage to create a straight mortise.