Shotgun - Choke / Scattering?
 

hi,
I tried searching through Basic, High-Tech and some Forum-threads but I did not find a clear statement to shotgun-choke in GURPS yet...

On B409 it is explained that e.g. RoF 3x9 releases 27 buckshot pellets and then shooting on a single target is just normal rapid fire.
- But what if I try to shoot e.g. on the center of two or three targets in hexfields next to each other in a distance about 40 yards?

Answers I've seen yet, seem to imply that the scattering-effect is usually overestimated and is not significant for the resolution of the game...?
Or is there a rule for this effect anywhere in the RAW?

I would have thought that a little "spread"-effect exist, since e.g. stories about past combat shotgun usage in Vietnam claim that it was effective against multiple targets. In a wikipedia-article it is said that a 12 gauge shotgun at 40 yds distance can have a total spread of 59 inch (150cm).
( http://en.wikipedia.org/wiki/Shotgun#Pattern_and_choke )

Shouldn't this be enough to justify at least some "partial" hits (or chances to hit) in the neighboring hex-fields at that distance?
(Maybe something like the rule for "Missing the Wrong Target" on B389 could be applied for the neighboring fields?)

And then: How would the different hits be shared over multiple targets?
Maybe in a similar way like the "Spraying Fire"-rule on B409 but with equal distribution?

Re: Shotgun - Choke / Scattering?
 

Chokes are covered on p.24 of Pulp Guns 1.

Edit: Having said that, I'm not sure that those rules would help you. The default GURPS assumption appears that either the choke is open or that the gun isn't fitted with one (as apparently most police/military shotguns aren't). Those rules deal with closing the choke to increase range. Therefore, that sounds like the opposite of what you're looking for.

Re: Shotgun - Choke / Scattering?
 

I would just go with the whole missed shots section rules, and start with that. There are rules for if you shoot at a target, you miss, where does the bullet go? Does it pass harmlessly, or does it hit some one else? Since we are talking buck shot, there will be a lot of extra pellets flying around. But going that way may not be too unresonable. But remember, to get that to work, they targets should be very close to each other. A 59 inch spread is only about 5 feet, and that is at 40 yards. At that rate, that would mean a little more than a 1 foot spread at a range of 10 yards, not much of a spread pattern. But if the two targets are side by side, touching each other, then maybe you might try something like that. It is one of those you have to make final choice on whether or not to do something like this.

Re: Shotgun - Choke / Scattering?
 

If default for shotguns is that choke is open, then I wonder where are rules for the scattering-effect? Or is it really assumed that there is no significant spread at all?

Anybody knows how the official perspective is on this?

Re: Shotgun - Choke / Scattering?
 

Not sure about the official perspective, but the current rules work decently well as a gameable abstraction. The alternative would be to write out the maximum number of hits on creatures of each SM at various ranges, give the ranges the correspond to each amount of spread, and treat shotgun blasts as something like an Area Effect Bombardment. That really just makes shotguns too complicated.

Re: Shotgun - Choke / Scattering?
 

Not official, but I assume that there is no effective scattering.

That Wikipedia 59 inches at 40 yards sounds a little large for buckshot. It's less than 2 full hexes coverage anyway. It's also -8 to hit and right at the 1/2D limit.

If you really, really had to have rules for shotguns at that distance you could adapt the Suppressive Fire rules and call it 9 or less to hit anybody in the area (though probably only once).

I'd say that the whole thing wasn't worth the trouble.

Re: Shotgun - Choke / Scattering?
 

The "official" viewpoint is in line with reality: Shotgun blasts spread enough to improve your odds of connecting with something when engaging a point target, explaining why shotguns are used in rapid-engagement situations. Blasts of shot don't spread sufficiently to strike multiple targets, although shot that misses the primary target might hit others along the imaginary line defined by the shooter and that target . . . just like any other stray. It's true that out at ranges where shot has lost most of its effectiveness, there might be enough spread to hit two people. In general, though, the idea that shotguns can usefully engage multiple targets within their effective range is a mix of mythology and wishful thinking – neither of which are things to which skilled shooters and combat vets are immune.

Re: Shotgun - Choke / Scattering?
 

Yeah, go with "hitting the wrong target".

On a related note, would it be reasonable for extremely high RoF weapons to use something like the rules for shotguns at point blank? I'm thinking "RoF 10, multiply penetrating damage by 10" for the RoF 100 minigun in my Supers campaign.

Re: Shotgun - Choke / Scattering?
 

thanks for the explanations!
Just wanted to be sure that I didn't overlook a rule or something ;-)
In appropriate cases with the right distance (rare), I'll use "Hitting the Wrong Target".