Inconsistent Firearm Stats

[Kromm]

Originally Posted by fula farbrorn

and thats one problem, how to measure and quantify MOA into acc

You can't. I might know relatively little about guns, but at the rules level, we made a "command decision" about Acc in general: It's mostly about comfortable handling, plus modifiers up or down for macroscopic features you can't ignore, like shooting match-grade ammo, having a longer or shorter sight radius, or the presence or absence of sights. If a gun has a reputation as "good to shoot," it'll likely have higher Acc regardless of its performance clamped into a rest on a range.

[MrFix]

Originally Posted by Kromm

You can't. I might know relatively little about guns, but at the rules level, we made a "command decision" about Acc in general: It's mostly about comfortable handling, plus modifiers up or down for macroscopic features you can't ignore, like shooting match-grade ammo, having a longer or shorter sight radius, or the presence or absence of sights. If a gun has a reputation as "good to shoot," it'll likely have higher Acc regardless of its performance clamped into a rest on a range.

Is the other side of the coin true? If a gun has reputation for being inaccurate (like AKM), that'd cause it to have less Acc baseline regardless of it's performance?

[Kromm]

Originally Posted by MrFix

Is the other side of the coin true? If a gun has reputation for being inaccurate (like AKM), that'd cause it to have less Acc baseline regardless of it's performance?

Yes – as I said, "modifiers up or down." Somewhat subjective measures are used for several stats for ranged weapons (not just firearms), mainly Acc, Bulk, and Rcl, and to a lesser extent ST. These collectively define that abstract notion many call "handling." I know also that Range is somewhat like this . . . specifically, 1/2D is closer to "effective range for typical users" than any kind of mechanical property.

[MrFix]

I see, thank you.

[Kromm]

Originally Posted by MrFix

I see, thank you.

No problem. From most to least objective:

Cost, Shots (capacity), and Weight are the most objective. You can go look them up. They'll vary by model and magazine size – and in the case of Cost, by seller and market conditions – but it's possible to present real-world stats for a specific model as it was offered when it first entered the market.

TL is objective if you take year of release as deterministic. However, you get judgment calls coming in for weapons near the starts of new TLs, as well as for those that are notably "advanced" or "retarded" relative to their era's technology. Thus, it's mostly objective but there are special cases where it's subjective.

RoF is rounded to the nearest whole number. It's also subject to the game's assumptions about how guns work; e.g., anything over RoF 2 for something that has to be pumped or levered, or 3 for a semi-auto, requires techniques that drop your odds of hitting a target, so the useful RoF is listed, not the theoretical maximum in the hands of a robot. Within those limits, it corresponds to real-life rate of fire, and is purely objective for full-automatic weapons.

Damage and Max can vary a lot due to things like barrel cross-section, twist, quality of the seals, how much energy is needed to cycle the weapon, and so forth. Two guns of identical barrel length firing identical ammo might differ due to one transferring less of the energy to the projectile (and more to operating the action or to escaping gases), or due to one launching the projectile with more stable aerodynamics (meaning two projectiles with the same muzzle energy but one losing energy more rapidly to air resistance). This is functionally on the objective/subjective frontier.

1/2D has the same variability as Max . . . and also takes into account "effective range," which can get fairly squishy and subjective because it has an ergonomic component.

ST and Rcl are linked to real-world weapon weight and recoil to an extent, but have a substantial ergonomic component that's rather subjective, even more so than 1/2D.

Acc and Bulk are seriously subjective. They represent how well the weapon behaves. Yes, things like how long the barrel is matter some, but these stats are mostly "gamist" quantities that give skill modifiers in particular situations, and as such are more about "ease of use" than mechanical properties.

Shots (reload time) is subject to the game's assumptions about how guns work, like Rcl, but a lot more like a guess . . . so much so that I'd call it "gamist" and not very objective.

LC is just some made-up game stat that changes with your setting. As the concept is a pure game construct, whose only links to the real world are to "soft," social concepts that vary even from city to city, it's essentially the most subjective of all.

[MrFix]

This is a high value post right there, since it explains all GURPS gun stats in one place and certainly puts to rest past and future arguments about minutes of angle and stuff like that. I'll make sure to bookmark it.

[fula farbrorn]

Originally Posted by Kromm

Yes – as I said, "modifiers up or down." Somewhat subjective measures are used for several stats for ranged weapons (not just firearms), mainly Acc, Bulk, and Rcl, and to a lesser extent ST. These collectively define that abstract notion many call "handling." I know also that Range is somewhat like this . . . specifically, 1/2D is closer to "effective range for typical users" than any kind of mechanical property.

This also makes an awful lot of sense for a game that is about people shooting people, not benchrests shooting people.

[Kromm]

Originally Posted by MrFix

This is a high value post right there, since it explains all GURPS gun stats in one place and certainly puts to rest past and future arguments about minutes of angle and stuff like that. I'll make sure to bookmark it.

Thanks.

As a fortuitous coincidence, MoA and Acc correspond nicely. Doug talks about it here. You could even use his work to set Acc for real-world guns, if you want; Doug knows his stuff.

But be aware that this is coincidence. We did not assign Acc based on that table or a formula! We definitely tweaked it for sights, grips, reputation, etc. It just happens that the resulting Acc values mostly line up with MoA in real life.

[johndallman]

Originally Posted by Kromm

No problem. From most to least objective: ...

Thanks very much for this; it will be very useful for a forthcoming campaign.

[kenclary]

Originally Posted by MrFix

This is a high value post right there, since it explains all GURPS gun stats in one place and certainly puts to rest past and future arguments about minutes of angle and stuff like that. I'll make sure to bookmark it.

It should be added to the unofficial FAQ thread.