I took mine to the range today after a total tear down and reassembly last night for cleaning, some minor adjustments to the trigger spring and installation of a stronger Wolff spring and guide rod assembly. I experienced my first problems ever with my Sigma. A couple of FTE's and some failures to return to battery, both probably caused by the stronger Wolff spring. The good news is that it loosened up a bit and was much better at the end of the session. Also, it was much easier on the hand with much less recoil. Better follow up shot/target acquisition. I love playing with this toy. Note the trigger stop on the back of my trigger as part of the trigger job done on it. I also think I've found a way to reduce about 1/3" of initial trigger play in it. I'll let you in on the secret if it works. Keep posting reports on your gun and shooting experiences. I like to see what other Sigma owners are up to.
If the Hand All moves around during range sessions, you can use some 2 way golf grip tape and application solvent to eliminate the problem.