Quote (SAS_Random)
The other up-side of this conservation of energy is the amount of leading edge concussion and cavitation which often results in a devastating, blow-out exit wound.
Actually this point holds only for rifles. The velocity of a pistol bullet is mostly so low, that human tissues is flexible enough to absorb the concussion without damage.
Anyway the effect of bullets are a complicated issue when looking into such details. If you are interested have a look here: http://www.firearmstactical.com/tactical.htm (2nd point "wound balistic"; leading to http://www.firearmstactical.com/hwfe.htm ).
My botton line for swat:
- use jhp against unarmored targets
- use fmj against armored or unknown
- use fmj in pistols or if you need to shoot though glass often
(jhp expands and therefore looses a lot of energy after the first collision, even with glass)
In RvS I use fmj all the time to be able to penetrate some doors.
And no matter if fmj or jhp: be sure of your target and what's beyond
PS: another nice post Random 
Added (29/11/2012, 0:18 AM)
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Found a nice manual in the ITS forum with even more details about weapon ballistics in swat4: http://www.instinct-tactical-squad.eu/index.php?forum-showposts-81
(direct download link: https://docs.google.com/open?id=0B9QTt-3nfOxOUEpjMUZfU1oxNjg )