Those subsonics should do quite well. (the subsonics work best for silencer arrangements, don't they?) I used CBs and CB Caps, Shorts, etc. untill the price of those well exceeded the cheap, standard LR ammo. Now I buy the cheapest rounds I can find. I get some misfires occasionally, but have little invested and I always have ample time to reload...a trapped animal isn't going anywhere anyway. Any low-powered round is very sufficient at that close of range. I think that if you can apply enough force with a blunt trauma blow by hand, then wouldn't it suffice to say that the carrying force behind a subsonic .22 even if it is so low powered will certainly produce ample penetration results? A coyote may seem to possess unrealistic stamina out in the open when running after a shot, even with a high powered round through it...but point is in this situation they are on the end of a chain not out in open, and you can walk right up to them. I used to head shoot them for a quick drop, but they bleed profusely at the set, so I went to heart shots. It is only a small, pencil-sized hole at most, and if you put up the furs washed, etc. you rarely get docked for such small bullet holes whatsoever. Geez, how many coon make it to market every year that were spotlighted and dropped at greater distances with .22s?
Personally, I would just lean toward the cheaper off the shelf LR ammo vs. paying a little more for special subsonics. Just my opinion, though. I would wager you would see at best a marginal difference in your marketed hides between 2 holes (entrance/exit) and single holes.
One argument for head shots is that there are already two eye holes and two ear holes in that area of the pelt already...what's one or two more? And, there are limited applications for the face furs anyway on most species.
Jim-NE