I just bought a 407 yesterday and it didn't come with a mount. A buddy bought a 507 maybe 6 months ago, and it didn't either. In all my looking before I bought mine, I seem to remember reading that they used to, but no longer do.

I seem to always want a reflex sight mounted lower than a pic mount and rail will let me mount it anyway, so didn't bother me in the least.

It might be lonely at the top, but it's a bitch at the bottom.