.22 Snake-Shot Is Iffy
It "patterns" very inconsistently, in part due to your gun's bore/rifling spinning the stuff off on odd tangents and less-than-perfectly-symmetrical patterns. That's why shotguns are smooth-bore.
I once had a well-used .22 bolt-action rifle that did OK with snake-shot... out to about 15-20 ft. I used it to nail the industrial-sized Woodpeckers that liked to attack my house's wood siding at daybreak. Even then, the shot's killing power was spotty, so I went to a 20 gauge with skeet-shot.
The best use I've discovered for .22 snake-shot (handgun) was for shooting an infestation of mega-nasty Bumblebees. At 5 ft., it drops 'em about 75% of the time. Makes for great practice.
As for using .22 snake-shot as a first-shot/non-lethal "warning" on some street-punk mugger: Get Real, wake up and smell the coffee, and take a firearms self-defense class from one of the reputable experts. They'll tell you that IF you're EVER justified in shooting someone, then you're justified in shooting 'em 'til they stop any aggressive action that threatens your life. That means Shooting To Stop. Period. If you blast some miscreant's face with shot, his lawyer will sue you for his client's now-desperately-needed plastic surgery... on top of all the other "damages", like Stress, blah-blah, etc.
NO police organization issues snake-shot to its officers for good reasons (although certain depts. overseen by urban-liberal-pacifist mayors/commissioners, etc., would prefer their cops be armed ONLY with floral-scented/low-fat/organic insect-spray and -- for extreme situations -- rubber bullets... for their single-shot guns. If you "really don't want to kill someone, just hurt 'em a little," leave your snake-shot loaded gun at home and pack a John Kerry For Prez lapel button. You could hurt some mugger with its rusty pin -- plus, just like the Senator -- they'll be militarily qualified to be awarded a Purple Heart. (Those pin-pricks bleed... and sting somethin' awful.)
Of course, I don't play some Bambi-hugging PC politician on TV, so my suggested uses for snake-shot -- fun as they may be -- might just bring the Sierra Club and MoveOn.org/U.N. Peace Police down on your head.