As previously mentioned,
BT/MW PPCs are more of the "classic sci-fi raygun" style of
charged particle cannons whose salvos are described as "
cerulean arcs/bolts of man-made lightning".
Given such a weapon's vulnerability to the effects of
blooming and
beam absorption (both caused by interaction with the atmosphere), use of a "laser-induced plasma channel" (as would be the case with an "
electrolaser") is one possible solution.
A
BT/MW Plasma Rifle (developed by the Capellans as a man-portable version in 3065, an IS BattleMech-scale version in 3068, and a Clan BattleMech-scale version in 3069), on the other hand, uses a lasing chamber to convert a solid fuel (a cartridge of foam or plastic) into plasma and project it (via magnetic fields) as a stream or bolt from the weapon (giving the weapon a more "fire-like" appearance as opposed to the "lightning-like" appearance of the PPCs, IMO), similar to the real-life experimental equipment used in the
Shiva Star and
MARAUDER programs.
As such, Plasma Rifles are technically also "charged particle cannons", but of a rather different and less "classic sci-fi raygun" type than the PPCs.
IMO, part of the distinction would be which damage mechanisms are emphasized - the PPCs inflict damage primarily from kinetic energy, secondarily through electrical interference, and finally through heat transfer, while the Plasma Rifles inflict damage through heat transfer, secondarily through kinetic energy, and finally through some limited electrical interference (as highly-charged gas and magnetic fields are still involved).
Your thoughts?