I probably go through 500-600 interlocks a year between my 8mm' s and .308. I have no complaints, they shoot good. Never thried the Hornady light magnums- they sell for aroud $27 a box by me which is too rich for my blood.
Not all bullets will work best in all guns though either. I' ve had some rifles that shoot best with corelokt bullets, though SMK' s seem to work well in every application for me.