9mm or .40 s&w?

[mikhael]

9mm or .40 s&w? Also What is the most common caliber among law enforcement?

[sd_shooter]

Use the search feature, this is a weekly question.

Or use the Calguns google custom search, it sometimes works better:

http://www.google.com/cse/home?cx=018149931542195181678:pzxbzjzh1zk

Then read this article:

http://www.m4carbine.net/showthread.php?t=19887