My great gandfather had the same problem with raptors. He took care of the coyotes with a .270 or an Army surplus M-1. He would keep the lambs in the lambing barn as long as he could so as to reduce losses to raptors.
I hate barn sheep. They become knee breaking grubbers waiting for a meal. Sheep born on pasture and ewes who raise them that way are stronger, healthier, smarter, and produce lambs who grow much faster.