So, this issue cropped up recently in one of my Black Crusade games.
One of the characters was considering taking a noise weapon with the spray quality to counter hordes. However according the Core Rules as Written (pg. 349), spray doesn't have an impact on hordes--the necessary quality is Flame.
Now, as written, "A flame weapon used on a Horde hits it a number of times equal to one quarter of the weapon’s range (rounding up), plus 1d5. So a flame weapon with a range of 10 hits a Horde 1d5+3 times."
With flamers, this makes perfect sense, as the spray quality gives them an in-built limited range of around 30-40 meters. (damage @ 30 meters= 10+1d5)
However, other non-spray weapons can have the Flame quality, too. These create major balance problems, as far as I can tell.
Inferno Shells (pg. 173 of Core) give a weapon the Flame special quality. They can be used in any SP basic or pistol weapon.
If we take the RAW, an auto gun (100 meter range, average availability) with inferno rounds (scarce availability) will be able to do 25+1d5 magnitude damage against a horde. Similarly a stub rifle (120 meters) will do 30+1d5 magnitude, due to the flame quality.
For comparison, a Legion Heavy Flamer (very rare) with High Grade Promethium will be doing 13+1d5 damage against a horde (50 meters/4).
Hellish blast (pg. 221 of Core) is an exalted psychic power that has, among other things, the flame quality, a blast radius of psy rating, a distance of 30 x psy rating, and a minimum psy rating of 5.
If we use the range of the power to calculate magnitude damage, the power will be doing 5 magnitude damage from blast and 38+1d5 magnitude (30x5=150 meters/4=38) damage due to range.
Alternatively, if we treat the radius of the blast as the range of the flame, it will be doing a much more reasonable 5 blast damage and 2+1d5 magnitude damage from flame.
Flaming Melee (i.e. Flaming Gauntlets)
Flaming Gauntlets (pg. 61 of Tome of Fate) give unarmed attacks the Flame quality. How should this be interpreted? Should we go with range=point of origin? In other words, a punch has range of 0, and therefore does an additional 1+1d5 magnitude damage due to flame vs. hordes?
I think there are two issues at play here. In Deathwatch, Flame weapons had the in-built range limitation of the "spray" quality, so basing damage on flame and range didn't run into these problems. For weapons like incendiary missiles, they didn't have the flame quality--they just set things on fire.
In Black Crusade, however, Spray and Flame are two different qualities. I see two different scenarios.
1)The Spray quality was the intended feature that was supposed to do Range/4+1d5 magnitude damage to hordes. However, despite the introduction of the spray rule for Black Crusade and non-flaming spray weapons such as Doom Siren and Spore Caster, "Flame" was mistakenly carried over as the key anti-horde quality. This would make sense, as spray severely limits weapon range, and counts as auto-hit across its 30 degree arc.
Solution: Spray should replace the Flame entry on page 349.
2) It was intentional to make Flame the operative characteristic for horde magnitude damage, as the Game Designers didn't want to extend anti-horde qualities to noise and other spray weapons. However, the entry on flame was carried over without considering psychic powers, inferno bullets, and melee weapons.
Solution: Flame damage to hordes should factor in the point of origin of the flame. A flamer remains unchanged, as the flame will originate at the full range of the flamer. However, inferno rounds and melee attacks will be treated as having 0 range, and so do 1+1d5 magnitude damage, while blast weapons will do only the radius of the blast/4+1d5.
Thought? Input is welcome!