This is a topic that just came up recently where upon discussing the capabilities of Gargoyle T we stumbled upon and all involved seemed unsure as to the answer.
Do Clans have access to Precision Ammo? Someone mentioned that they do not but nobody could confirm or deny this. While in MegaMek they do, as an unofficial product we could not be certain whether this is an error or confirmation.
I would find it most interesting if they do not as they certainly do not seem opposed to the benefits of Pulse Lasers, Targetting Computers and Artemis V.