The ProtoMech Autocannons are a series of weapons introduced by Clan Blood Spirit in 3073. Scientists from that Clan, using old prototypes from early Clan experiments in lighter autocannon technology, developed them in order to add additional weaponry to ProtoMech arsenals. When mounted on ProtoMechs, these weapons do not generate heat and thus do not count towards the ProtoMech's heat budget.
The wording in the Tactical Operations states that all of the advanced weapons described could only use their own standard ammunition types unless otherwise noted, but in the description for ProtoMech Autocannons it states that they use all the same rules as conventional Autocannons. According to developer Errata, the ProtoMech Autocannons can use alternate munitions.
There are three sizes of ProtoMech Autocannons:
- Tactical Operations, p. 284 – 286, "ProtoMech Autocannons (Proto-AC)"