I want the deepest penetrating and most reliable round possible for my NAA mini revolver. I figure I should go FMJ. I want penetration to go through a pittbulls head or attackers coat.

I am down to these two rounds.

http://www.cabelas.com/link-12/product/0064202216860a.shtml?cmCat=perf&rid=0987654321&cm_mmc=Performics-_-CSE-_-GoogleBaseUSA-_-0064202216860a&mr:trackingCode=6B8799CB-958E-DF11-A0C8-002219318F67&mr:referralID=NA


http://www.cci-ammunition.com/products/detail.aspx?use=1&loadNo=0063




Wish buffalo bore would make a lead hard cast flast nose .22 magnum with CCI primers.

Would a shot shell like this do anything to an attacking human?
http://www.cci-ammunition.com/products/detail.aspx?use=1&loadNo=0025

I'd do some testing if I were you on wet phone books tied together.
You do realize this is considered a last chance gun right!
I'd not trust a 22 cal rimfire to go through a large dogs head unless it was comming from a rifle and still I'd want at least a centerfire round.
I also carry a 22 mag derringer at times, but only as a backup to a 38 or 45.
You may find, as I did, that a Ruger LCP is easier to carry and gives you 1 in the tube and 6 in the mag in .380 acp.
Bigger is better and more rounds are better yet.

Have you seen this ?

Compares velocities of various ammunition through the different NAA handguns.

http://www.northamericanarms.com/naaveloc.html

Penetration tests of 22 magnum when fired from a 2 inch revolver.

The four tested loads all penetrated in excess of 14 inches. The CCI 30gr Maxi-Mag JHP rounds penetrated 14.3 inches.

The velocities out of the NAA Mini are slower than the 2 inch revolver in the tests, and penetration will be less.


ETA: found a better link at the same site where the NAA 22 mag (1 1/8 inch barrel) is tested for penetration with various loads.

The CCI 30gr Maxi-Mag JHP rounds penetrated 11.4 inches.