Re: Fiasco's journey to lockpicking
With the M1 you have to use medium to hard torsion as they have a strongly spring loaded core and you are right, there is very little feedback.
Stick with the half diamond - strong torsion and lifting and raking the pins. All of a sudden it will go.
I've tried another one (besides mine) and that's how I got it.
Good luck.
PS. We all have at least one lock (or a "naughty Box" full of them) that is really stubborn. You will get it - eventually.
For every expert there is an equal and opposite expert.