for longer range i prefer to put my weight in a barrel not a piston that bangs back and forth to stress the optic's durability. if dead-set on an autoloader in 6.5 CM i would go with an LR-308/SR-25 pattern rifle because it's going to give options on barrels and the recoil impulse will be smoother.
if you really want to hammer things at range build yourself a 6.5 CM from a Howa or Savage short action into a chassis something like a KRG or MDT. at longer ranges such a build will shit all over a Sig 716. BTW have you shot a LR-308? it's plenty of gun in .308. a well tuned LR-308 isn't the easiest to build but if can be make reliable they are a lot of fun. unfortunately with a solid optic they're usually heavy as hell. Sig's website lists the 716 as 9.5 lbs. add some glass and it's going to be a 12 lbs. further, keep in mind barrel life. the 6.5 is not going to have nearly the barrel life of a .308. and when going semi auto the difference in barrel life will likely be even more due to faster shooting = hotter barrels.
i dig autoloading rifles but after going through a phase where i wanted everything to be an autoloader i've slowly settled back on bolt actions as being easier and cheaper to accomplish high levels of precision. something like this Howa 1500 6.5 CM in a KRG chassis is going to be stupid accurate. it's 10.5 lbs but has a 26" barrel (10 more inches of barrel than a Sig 716) to allow that 6.5CM to really get rocking. there's no way Sig is going to put a 26" barrel on the 716. i've recently gotten into the howa rifles. i'm super impressed by the build quality and action. they make a R700 look like garbage.
https://www.brownells.com/firearms/...o-6-5-cm-26-fde-10-1-threaded-prod115731.aspx