The Hornady bullet is a soft, squishy swagged bullet for target shooting. It is not a Hard Cast bullet.
So thumping them up with a fast powder you will probably get leading. Pressure wise the M686 is fine it is meant for full house 357 mag loads.
But then we can get into the TG debate again.
Why use expensive Hornady bullets for shooting steel??
JMO but perhaps use 357 brass and a hard cast lead bullet and use start 357 mag loads or just change the bullet if you want to use 38 brass.