Lot's of inconsistencies, as usual.

But, Miller's scope. The one with the flashing dots at the bottom. What is that? Airsoft? BB gun? Or, something so far out of my price range I've never seen one?

Is this the original Sniper (with Billy Zane, in Panama) or one of the multiple sequels?

Google's AI states that it is a Leupold M3 Ultra 10X, although I don't see any flashing dots on it.

IMFDB says Miller used a Heckler & Koch SR9TC, but it doesn't reference the scope, Link

Incidentally, that H&K SR9TC was used in several movies after Sniper to included Under Siege 2, Heat, The Jackel, US Marshals, Replacement killers and others..

Link Movies