My advice on the .25 mrod is to oval out the transfer port on the barrel, drill out the transfer port, and install a heavier hammer spring, and call it good. Any more money you put in after this point (a $4.00 spring), you might as will buy a different gun that will already have what you want. I've read people turn their mrods in to 30 cals or into .257 bullet shooters but at the cost of just buying a texan, and you could have more power and better performance. I was in the same spot as you when I had my .25 mrod and what I did was I sold my mrod and bought a used .25 sumatra and had Wil Piatt power tuned the sumatra in to a 104 ft-lb monster.