I know a couple of cowboys with the older micro-groove barrels. They have not complained of any problems. With the cowboy all lead bullets, the deep ballard cut rifling is suppose to be better. The purpose of rifling (as you know)to put a spin and stabilize the bullet better. Another factor for the cowboys is that we are shooting some pistol calibers that were not really designed for rifle. I mean if your going into the woods, you are going to take a 30-30 or 44 mag, not 32.20 or 38 special. The Marlin Cowboy I and II are certainly a success. That's hard to argue with. Just my two cents.
