Done this experiment many times but still cannot figure out what it proves. The balance point shows that half the mass is on one side and half on the other, it says little about the feel and handling. I have also managed to balance a SXS with 5 lb arm exercise weights at its extremities.
Much more can be determined by balancing each part, barrels, stock and action, separately to see how they concentrate their mass. The more towards the centr the balance point, the more lively the total gun.
As for the actual technique, a piece of leather or other non slip material over a chair back is reliable enough support. Kust be close enough and ready to catch.
