I don't really think much of the concept of putting a scope on a handgun. To my way of thinking, handguns are defined by their portability and compactness, and adding a scope to one adds bulk and weight, i.e., it makes them the antithesis of what they're designed to be.
However, in the past 30-40 years hunting with handguns has "come of age" and there are many guns designed for this to which the term "compact" doesn't apply, and "portable" is dubious. The ghastly S&W X-frame revolvers, for example, guns which dwarf the .44 Magnum Dirty Harry carried, are not really "handguns" because a) you HAVE to shoot them with two hands; and b) they're so big they require a sling to carry comfortably. They're really short carbines.
I'm always willing to look at an issue a couple of times, however. Furthermore, since I'm about to complete my sixth decade, my eyes aren't what they used to be, and my ability to hit things with a handgun isn't what it used to be either. So I decided I had at least one pistol that was worth experimenting with.
I like to carry a .22 with me when I hunt deer. This is legal in Virginia in the rifle season, and usually I've brought along a nice Ruger Single-Six revolver for the purpose. However, far and away the most accurate handgun I own is a Ruger "Standard" Autoloading Pistol I bought in my college years. Forty years ago I paid the magnificent sum of $41 for this gun, brand new. In those decades it's been used as a trainer, mainly; it's had at least 30,000 rounds through it, but it's as good as the day it left Southport in 1967.
I wanted to minimize the alterations and looked for a no-gunsmithing mount base: there's no way I'd allow holes to be drilled in this pistol. I found a couple of varieties of these, but the lowest-profile (and hence most suitable) one is made by Weigand Combat Handguns. The rear sight of the pistol is drifted out and the scope base put in place of it, then locked down with setscrews. Very neat and well-designed and it appears to be rock solid. I chose a BSA 30mm Red Dot scope for it, a model that's worked well for me in the past on a .22 rifle. It has a standard Weaver mount and mated to the Weigand base perfectly.
I'm convinced. I had the combination out at the range yesterday and my God, does it shoot. Once I had it sighted in, using Federal's bulk high-velocity HP's, it was a matter of "put the dot on what you want to hit, pull the trigger, and you hit it." Every time. As a take-it-along-in-case-a-squirrel-pesters-you gun, this is IT. I can hit a squirrel in the head from 25 yards off, provided I have a good rest and he sits still long enough. It shoots way tighter than I can hold it, but the gun always could. The sight takes advantage of the accuracy potential inherent in the pistol.
I'm not about to put a scope on my Kel-Tec .380, nor on almost any other handgun I have, but this looks like a permanent arrangement. Now all I have to do is figure out how to carry it conveniently when I go into the woods.
ADDENDUM, OCTOBER 21, 2013
After returning from my elephant hunt in Namibia, I decided to switch my .416 back to open sights. This left me with a very nice Aimpoint Micro H-1 red dot sight needing a home. The Aimpoint is a very expensive and high quality product, and it's perhaps half the size of the BSA shown above. So....it got put on the Ruger and I sighted it in. Any squirrel with 25 yards is going to get shot in the eye using that rig.