I had an AR-10A2 for about a year, it had the factory Match Trigger, the ARMS Extended mount and a 4x12x44 Nikon Monarch scope on it. I had six mags that were the Armalite kits, which were Armalite factory converted M-14 mags with my springs and floorplates, these puppys ran about $85 each with all the shipping and so forth.
I fooled around trying to fall in love with that rifle for a long time untill I got an Arizona Response Systems (ARS) Stg-58 FAL, then I sold it, and never looked back.
The AR-10 went back to the factory for the bolt recall, had the the factory polish out the chamber because of terrible extraction problems and never really got the $85 mags to work good enough to shoot an IPSC match with it. The accuracy was just ok, shot 2-2.5 inch with most stuff, Fed Match was good for 1.5 and surplus was good for about 3 or so.
I got the FAL and it didn't jam at all with the $6 mags and it got the same size groups with it's iron sights and a military (read "heavy") trigger. I just put a DSA scope mount on it with a Leupold M8 2.5x Scope and that is a blast. It is not a sniper rifle, it is a battle rifle. It is not super accurate, but it is super reliable, my AR-10 was neither, but it was more expensive!
I'd buy a DSA Stg rifle to stay under 1k, it is "the right arm of the free world"
battle proven by 80 countries.
Bill