I have a Ruger 77/357 which fires 357 magnum and 38 special ammo. I'm looking for a optic that would be in the 3 thru 9 or 4 thru 12 magnification that would handle the bullet drop between the two calibers. If I sight the rifle in with the 357 mag it will be dead on in that caliber but when I usee 38 special in it it drops the bullets about 8 inches POA. I would like to find something with a bdc or mil-dot optic that I could use without having to adjust the scope everytime I change calibers. Any suggestions would be greatly appreciated...