The Mossberg MVP Thunder ranch is a very capable gun with a lot of bells/whistles.
External magazine fed, Threaded, Fluted, Adj. Trigger, and it comes in OD Green. For 550-600 you cannot beat it.
You will have great success at Briar Rabbit. Further than that you should have consistent hits to 800y if you are using good ammo. Well, Put it this way. My Bull barrel AR15 goes nuts deep to 675 with cheap PMC 55g plinking ammo. You should have no issues getting to 800. Maybe further?
I also have a couple scopes I can sell you. PM me