I look to use the forums to ask questions, and the primer for the thread says that I should contact Customer Service directly. Start going to customer service, and it says I should ask on the forums first. As such, I have no idea if I'm doing this properly or not.

I'm working on a personal project that I won't go into too much detail about, but long story short, I have hit a snag. I can't figure out the ranges for the heavier guns in 40K. DH and other 40K RPGs do a good job offering somewhat realistic ranges for firearms, so I've been using those stats. However, there are two problems with this

1) DH hasn't statted any weapons any larger than Autocannons or MP Lascannons

2) The scale between 40K and DH ranges isn't consistent. Just as some examples

Laspistol - DH: 30 Meters. 40K 12"

Lasgun - DH: 90 meters. 40K 24"

Heavy Bolter - DH: 120 meters, 40K 36"

Lascannon - DH: 300 meters, 40K 48"

So we're looking at really haphazard jumps between the ranges. Between 1' and 2', there's a 60-meter jump; Between 2' and 3', a 30 meter jump; and between 3' and 4', a 180 meter jump. This is fully understandable, as 40K scale is more of an arbitration for the sake of fitting everything on a tabletop, but it doesn't make for cohesive conversions to scale distances. When I tried converting the actual ranges of 40K to scale distances (28mm), guns fell flat on their faces, with weapons that fired roughly 20 meters per foot of 40K range.

Now, I'm not sure what's slated to be included in the Only War supplement, but just in case it doesn't include all the stats I'd be looking for, I'd like to know what the longer ranges would be represent in Dark Heresy. For example, a 60" weapon, a 72" weapon... or one of those 240" artillery pieces... Knowing how far out they actually reach is all I really need at this point, to continue work on my project.

Given the different scope of the games as well as the examples the official designers have put forth, I would say you do not have to even try to gauge some kind of system behind those numbers. As long as something that has a longer range or does more damage on the TT is represented in a similar way in your conversion it's all good, regardless of the missing level of detail.

If it helps, though, there's an RT book that mentions mortars have a range of ~300 meters. For really large pieces of artillery I would not even bother with writing down numbers since you're well into kilometer-scale here, at which range simply becomes a narrative tool, not a mechanical one.

This is a good point, however, what I'm looking to do with these numbers is more on a larger scale than DH's player-scale. More on a vehicular scale. Think Epic 40K. The only reason I'm not using Epic 40K is that it has ranges very similar to those seen in standard 40K.

I'm asking about the ranges for gear like the Battle cannon or the like because it's the kind of gear that's going to be the most relevant, even if medium range for an artillery piece goes into the tens or hundreds of kilometers.

Lynata said:

Hmm considering that even outdated ww2 light mortars had about 2000m range, DH ones should have at least 600 meter base range if they should even use the standard range system. Since it fires indirectly with forward observers I don't see why range should make it harder to hit really.

the only thing I could suggest on a similar yet slightly more extreme range would be converting some of the Rogue Trader ship combat rules.

Ice_trey said:

Hmm, in that case, perhaps taking a look at the mass combat rules from RT's Battlefleet Koronus would help? I've just heard it includes artillery range, but given that I don't have the book yet better have someone else confirm this.

Friend of the Dork said:

Well, as per the standard rules, a weapon's given range isn't exactly the maximum but only the point where it becomes harder to hit. Weapons cannot fire at targets more than 4x their range, though, which in case of the mortar means 1200 meters.

As for the range penalty, I could see distance making it harder for the observer because he has to guess the range and potential movement of the target, not to mention atmospheric conditions such as strong wind etc that have a stronger effect on the shell the longer it is in the air. Firing a mortar with a spotter does give a +20 BS bonus and limits the scatter range, though.