(I wanted to make this a poll, but apparently I took too long to type because you only have a 5 minute window.

)
Simple question for half-assed science time!
Your gun shoots X fps. Assume X is consistent and high enough that you would maybe think twice about shooting someone at close quarters.
Do you think putting lighter ammo in your gun would hurt someone more, less, or the same? (In other words, would the lighter BB transfer more, less, or the same energy?) Why?
Bonus related topic:
Many people transition to sidearms when getting into close quarters, since most guns nowadays shoot pretty hot. Now, other people bring up the fact that doing it for safety's sake is a little weird since modern gas pistols actually shoot at least as hot as most electric rifles nowadays.
All other things being equal, do you think putting lighter weight ammo (like, .12s) into your gas pistol would help this?
Updated with test results! See this post.
Updated with a small duplicate test using floral arrangement foam, and a penetration test between .12 and .43. See this post.