Survivor is no more realistic than any of the so-called Reality shows.
Suns of Guns is pseudo entertaining if you really don't know much about guns or gun safety.
Top Shot has some interesting challenges, but is corrupted by the fabricated drama between competitors.
One Man Army, while admittedly I haven't watched it, reminded me of another show called Special Ops Missions, on the Military channel (which is part of Discovery).
No gun shows are directly aimed at the demographic that largely encompasses THR. We know too much and will nit pick safety and terminology that the average joe either doesn't know about, or doesn't care about. Gun guru's are not the target demographic. Not saying I'm a gun guru, but I know more than average joe, I assume, who is the target demographic.
Personally, I'd rather spend an hour shooting than an hour watching a TV show about other people shooting.