I was shooting loads today from 70 - 110 grains of two different powders. I was shooting 250 grain Shockwaves and 200 grain Hornady XTP's. Not a single keyhole no matter what the powder charge.

I have noticed more keyholes in hot weather then cold weather. The reason for them I have no idea. Maybe the sabot and projectile are more prone to sticking together longer which would cause an erratic flight.