Kannonfyre,
Here are the ballistics from each of the company's web sites.
Bullet Muzzle Muzzle 50 Yard 50 Yard 100 Yard 100 Yard
Weight Velocity Energy Velocity Energy Velovity Energy
Mini Mag 36 gr 1260 fps 127 ft/lb 1118 fps 100 ft/lb 1035 fps 86 ft/lb
Win
Pwrpts 40 gr 1280 fps 146 ft/lb ? ? 1001 fps 89 ft/lb
Their performance is close but the Winchesters seem to carry a little more energy, probably because the bullet is a little heavier. The CCI's may shoot an inch or so flatter at 100 yards.
The more important question is which will shoot in 'your' firearm most accurately. The only way to tell is to try them both in the same firearm, if they both shoot identically (which they probably won't) then get whichever is on sale at the time.
One of the oddities about 22 lr firearms is that each one is an individual and two seemingly identical firearms will shoot differently with the same ammunition, the only way to tell is to perform your own test then stick with the brand that works best for that firearm.
As to the effectiveness against small game....well....you have to hit it first.