I have done a lot of penetration tests with .22. This next picture is a cheap Remmington thunderbolt 1250 fps into a fresh deer head at 30 yards. The bullet was recovered and mushroomed to .36 caliber and blew out the opposite side of the skull. The deer itself was harvested using my crossbow and I took the still warm head as soon as I got her home and performed the test. The first pic shows the entrance hole the second shows the exit and the third shows the exit after I inserted my finger into the brain. The entire area around the exit hole was shattered and trama was severe. This test proved to me that I can use my .22 for any Game harvest up to deer size animals. I also keep over 14,000 rounds for our .22 rifles. Unlike Gun Kid I do noy see the .22 as a first line defensive weapon BUT;;;; If I was on the run with no re supply I would carry my Ruger 10-22 and 2,000 rounds. My AR-15 would be left behind. I use a Marlin 981-T bolt action with a redfield revolution scope for game taking. It is deadly accurate. I can make this head shot on a deer every time.