Is what enough? Enough shots to incapacitate someone? One .22 LR to the brain usually does it, despite what some armchair wound ballistics experts claim. Its like turning off a switch when it hits, all movement stops.
Ask people who used to slaughter hogs, beefs, etc one .22 LR to the forehead was all it took. Back in the day when farm families would get together to have hog killings on each others farms, my Dad did all the shooting he never made one squeal even. They all hit the dirt dead as wedges, from a .22 to the brain.
Of course he was using a .22 rifle, but at two or three yards, the Mini-Mag Copper plated 40 grain roundnose .22 LRs I use in my Model 71 penetrate well.
"No free man shall ever be debarred the use of arms."- Thomas Jefferson