Take a look here: Rapid Access Targeting System (R.A.T.S.) By Dog-Gon-Hit Review
I've carried this unit around the sage brush simulating coyote hunting conditions enough to have faith in its use when the time actually arrives to go shoot some coyotes.
I made a couple of small mods to make it fully satisfy my personal preferences.
It works great with rigs from my SIG-556 (AR-15 type) through up to an 8 pound 338 RUM and 10 pound 270 Win sportier.
It has a bit of a problem with extremely front heavy rigs such as my 17 pound 30" barrel with massive brake 375 Allen Magnum and my long front heavy 270 Allen Mag. These are extreme longrange rigs and are shot prone w/bipod.
When set up properly I'd be confident with it beyond 450 yards or so. We'll see for sure one of these first days.
It's worth consideration.