The Masterlocks have a different 'feel'. Maybe because the cylinder 'floats' in the housing, not sure. Although it took a day or so to get used to it, I can pick Masters regularly. However, I know what it is like to get 'stuck'. Maybe its time to try a different tact....
Most #3 & #5 Masterlocks can be raked, you have to use light pressure on the wrench and it takes some practice before you know the lock is picked and the cylinder is ready to turn so you can turn up the tension on the wrench. Maybe you should practice raking them first to develop a sense of wrench pressure and then work on the picking. After all picking is as much the wrench as the picks.
Just my 2 cents...
