I've never had any luck with 180Gr. lead bullets. Copper washed bullets work so the hi tec coating may just help. I would like to try some of those as well.
The other thing I had been thinking is that a slow burning powder with a little heavier bullet might make it easier to get the rifle to function properly at the maximum 1400 fps that Zoot Shooting requires. Would it be possible to take a heavier (200Gr. or more) over size bullet, say a .357 and size it back down to .351?