AR rifle buffer questions

[tdbru]

thanks guys. i was curious how a heavier (i.e.tungsten weighted) buffer would slow down the point at which the whole mass moved far enough back to expose the end of the gas tube. theory i am wondering about is, if the reciprocating mass went up enough, the gas pressure at time of gas tube exposure to the action interior would be way lower due to the longer time for more recip mass to move enough to expose the end of the gas tube. hopefully resulting is less carbon deposit in the action. i.e. a cleaner action. since my setup is a semi anyway, lengthening the cycle time is a moot point. it still is ready to go again way before i am. can't really add mass to the BCG unless they make Tungsten BCGs, but i've not seen any yet. so the buffer may be the only way to add mass to the reciprocating assembly. has anyone tried this experiment yet? gone with a very heavy buffer? did it make the action cleaner?
thanks,
-tdbru