Li'l Gun shouldn't have any problem burning fine in a handgun barrel.
In my particular rifle .221 Li'l Gun is the clear winner with 40's, but with 50's Accurate 2015, IMR8208 and TAC all get fine accuracy and top velocities. Neither RL-7 or Accurate 1680 is outstanding with any bullet weight, so it would probably pay to try as many as possible of the various powders people have mentioned here.
