I know that this topic has been discussed numerous times on the forum but decided to give my experience following an 8 day hunt in South Africa. Not 100% relevant to your question as the furthest shot was approximately 350yds.
I shared the sceptism of using smk's for hunting similar to many other members, but decided the only way to see if they worked was to hunt with them. Over the last 4 years I have become an extreme fan of smk's. Our latest 8 day hunt in South Africa cementing my belief in the fact that smk's can do the job (if you shoot the animal in the vitals of course). During the 8 days over 30 animals where shot with 3 different calibers i.e.
25-06 (100gr smk)
308 (168gr smk)
300RUM (220gr smk)
Distances ranged from 10 yards to 350 yards. Animals where warthogs (50 pounds +), springbuck (50 pounds), blesbuck (80 pounds), Impala (80 pounds +), Wildebeest (200 pounds +), Hartebeest (200 pounds +), Eland (1000 pounds).
Shots taken where head shots, shoulder shots, behind shoulder shots, and neck shots. The 25-06 with 100gr smk's at 3400fps has always performed well at longer (?) ranges of over 200 yards, but just as well at close ranges (under 100 yds ) on the smaller animals (100 pounds or less).
The 168gr smk's accounted for the majority of the medium weight animals (200 pound +). The 220smk accounted for an Eland and a couple of unfortunate springbuck. From my personal experience I would not hesitate to advise that smk's can do the job on hogs at 1000 yards.