I did a lot of .357 long range shooting back in the day with a six inch barrel ruger with mixed results. I entered the Phoenix shoot for underlevers this year with my Marlin 1894c. At 100 yards it's suprissingly accurate but it becomes quite vague as the range gets up to 300. It is still a pistol bullet with the aerodynamics of a brick, and the speed drops off very quickly. Drag is an inverse square law so doubling the initial speed quadruples the drag. You only have to compare a HV rifle bullet to a 38 swc to see why long range shooting is very much a rifle thing. Another thing to remember is that it's the BASE of the projectile which causes the most drag with a huge vacuum forming behind the bullet in flight pulling it back.
Not to say I wont have another go at the Phoenix this year though!
"Always try to learn from other's mistakes. You haven't time to make them all yourself."