They are fundamentally the same gun. The 682 has replaceable shoulders and a trigger adjustment for LOP. The 682 is intended as a target gun and is expected to receive a lot of use. I have yet to hear of anyone replacing the shoulders on either gun though. Hinge parts are renewable on both and can be done at reasonable cost, should it become necessary, Unless there is something calling you to a 682, the 686 will serve most mortals very well indeed; imo they are one of the finest guns ever built.