|20cm||used as infinite repeators on Mk XXXI onwards|
|25cm||0.5mt/s output, used by Mk XIV & XV and by Magyar-class battlecruisers|
|30cm||used by Mk XX|
|50cm||first model capable of orbital fire; used by Mk XV/R & XVI|
|60cm||used by Mk XVII - XIX & XXI|
|80cm||used by Mk XXIII|
|90cm||2mt/s output, used by Mk XXII & XXIV - XXVI|
|110cm||2.75 mt/s output, used by Mk XVII - XXX|
|200cm||5 mt/s output, used by Mk XXXI onwards|
The Hellbore is a plasmagun originally developed for use by the Concordat Navy but it has a long service as the main and iconic weapon of the Bolo. Until the development of battle screen in the late 28th century, a single Hellbore shot was capable of destroying almost any target and even after this it was typically a penetrating and highly damaging weapon. Hellbores have substantial recoil and Bolos have occasionally used them as an aid to manuevere themselves in a tight situation or even as improvised reaction controls in space.
The first Bolo to mount a Hellbore was the Mark XIV in the early 24th century, utilising a 25cm weapon originally designed for the main battery of the Concordiat Navy 's Magyar-class battlecruisers . This weapon was also used by most variants of the Mark XV but was retired by the 27th century when the 50cm and 60cm models came into use (by the Mark XV/R and Mark XVII respectively).
The Bolo Mark XX set a new precendent with the use of two Hellbores, albeit only 30cm models, but in general the size of the weapons increased from the late 29th century onwards with the 90cm Hellbore of the Mark XXII , Mark XXIV and the Mark XXVI replaced by 110cm models on the Mark XXVIII through Mark XXX (the Mark XXIII used a pair of 80cm Hellbores). In the 34th century, fighting the Melconians, Bolos were utilising 200cm Hellbores as their main armament and the 20cm Hellbore was adopted as the new Infinite Repeater at the same time. By the end of the war, the Bolo Mark XXXIII was armed with an unprecendented three turreted 200cm and fourteen 20cm Hellbores.
The Melconian Empire also fit hellbores to their heavier ground combatants.