Armalite and Knights Manufacturing are the best of the breed, if you don't go with Knights go with Armalite and EXCEPT NO SUBSTITUTES, it's one or the other here.
Hesse and ASA have both started off AR10 copies or ripoffs, both are utter junk and simply are not the sort of quality firearm that the Knights or Armalite rifles are.
Of the two, I prefer Armalite in that the rifles and accesories are much easier to come by and the Armalite customer service is said to be much more desirerable. If you simply have gotta have a rifle that has been adopted by the US military then go for the Knights SR25 but expect to wait for a new gun if you order through the company or expect to wait awhile until you find a used rifle in the condition and configuration that you want, expect to pay a bit more than the Armalite AR10 as well and the SR25 uses unique magazines that cost even more than the M14 converted magazines that the AR10 uses.
If both the Knights and the Armalites are too much look at Eagle Arms, Eagle being the sister company of Armalite has an AR10 variant that is just around 1k dollars but isn't quite as nice nor does it have the Armalite lifetime warranty.
