Over the past half century I have tried out a great variety of handguns for the small game role. These would include the S&W kit gun, Ruger Bearcat and single six, small to mid size .22 autos, .32 H&R mag revolvers, .38 specials of the lighter variety, T/C Contender in .22 and .30 carbine, etc.
While there is no one gun that is "best" for any and all situations, I have narrowed my selection down to these two and with a very strong preference for one of them.
The AMT Automag ll in .22 WMR is a splendid little gun, it functions reliable with ever brand and bullet type I could find. From its six inch barrel I've chronographed 50 grain bullets over 1200 fps, 40 grain loads at 1400fps, and most recently the Remington 33 grain V-Max topped 1800 fps. That is plenty of flat shooting power and with the Burris Fastfire sight I've gotten one inch groups at 25 yards with several brands of ammo. From a solid field position I believe I'd have a pretty fair chance on the "larger small game" like jack rabbits and marmots out to 100 yards. But take away the rest and I'm just too shaky to be confident of braining a bunny at 25 yards and as for taking the head off a grouse, I'd need a rest at 15 yards. So that is where the other gun comes in.
It is a Super Comanche .45 Colt/.410 but forget the .45 Colt, mine is strictly a .410. I removed the rear sight and cut the sight boss down to a clean barrel. I also reduced the front sight by the same amount. This makes the gun a lot slicker into and out of the holster and makes it a "point & shoot" piece with no rear sight to clutter up the view of running or flying game. The grips are a "work-in-progress" at this point. I have a couple of slabs or rosewood coming which will be made a bit longer than the frame to resemble my favorite single action grip style, the 1860 Colt Army model. These guns throw a remarkable pattern with 3" shells of #6 or 7 1/2 shot, much better than the T/C Contender I owned thirty years ago, and are sure death on birds and bunnies at 25 yards. I may have to pass up an occasional animal out of range of the shot shells that perhaps I could have taken with the .22 WMR but that is more than compensated by the fact that I can hardly miss anything within range, even running or flying I have a pretty good chance.
As photographed the Super Comanche weighs 36 ounces and the AMT .22WMR weighs 31, hardly a noticeable burden in a good spring clip shoulder holster. I made such a holster for the AMT and as soon as I've finished one for the Super Comanche it will be accompanying me a lot more. I find the 10" barrel sacrifices about 200 fps, that is actual chronographed loads from the pistol run about 940-980 fps versus the factory claim of 1150 fps for a 26" barrel. But even at that reduced velocity #7 1/2 shot seems adequate for game as large as jack rabbits and will drop a grouse without a quiver. While .410 shotshells are outrageously expensive for practice and play with clay birds, one box will last several years if reserved for actual hunting. These guns are not terribly accurate with .45 Colt loads, the reason I shed no tears over eliminating the rear sight, but I suppose it could be handy to carry along a couple of shells in case of a close encounter with bear or cougar. I have fired a lead bullet .45 Colt through the shotshell choke tube with no damage but that would be an emergency last resort. Firing shot loads through the .45 Colt tube produced a very nice, even pattern, much larger than with the shotshell choke but still effective to 20 yards and would be a better choice for snakes at short range.
For a small game pistol the Super Comanche would be hard to beat even before considering the retail price of about two hundred bucks.