Shotguns and RoF... is there a better way?

[Ulzgoroth]

Back on the original topic of short range shot use, the rule represents the way undispersed shot act somewhat like a very soft slug, blowing one big hole rather than lots of small ones the way pellets that have had room to spread some will.

Originally Posted by kdtipa

So in the third situation listed there... 7 pellets hits out of all three shots fired... it looks to me like 7 of the 9 in the first shot actually hit, and none of the following shots had any pellets that hit anything. If I'm firing at three separate targets, that means I only hit one of three targets. Or am I misunderstanding something still?

I'd like to see a write up of how the rolling happens. Sticking with the pump shotgun from the basic set, and imagining a person with zombies or something closing on them quickly. The person in the scenario fires one shot at each of three zombies in the first round. How do you roll that and figure out how much of each shot hit each zombie?

You have to roll a separate attack against each target. You can never directly engage multiple targets with a single attack roll. (You could indirectly by firing grenades or something of the kind at a single location which will cause damage to multiple targets.) The 'normal' use mode of RoF > 1 weapons is to fire all the shots at a single target.

[Tomsdad]

You better on GURPS than I am, do you know of the top of your head is you can suppress fire with NxM rounds? (even normally or for increased 'N' options in HT/TS)

[Fred Brackin]

Originally Posted by Tomsdad

The following brings up a point though, RAW has it that only ROF5+ can spray between targets. In HT it says that rapid firing (i.e increasing the number of semi automatic shots you fire per second by taking to hit penalties doesn't count for this) now the question is does 3x9 count as 27 in terms of allowing spraying fire or not.

There is a deliberately unrealistic Perk that allows this but it is not possible under normal rules. You've only got 3 shots fro the purposes of most autofire rules. You only go to the Rapid fire table when you total up all your shots at one target.

Note that it is a Rapid fire situation if you fire 3 shots from a RoF 3 pistol too. You also can't fire each shot from that at a separate target. Even the second target gets you the -6 penalty discussed above.

A third target (at a cumulative -12) from a single might be allowed in a very cinematic game but normally to perform such a feat would require actual Advantages such as Extra Attack with Multistrike or Altered Time Rate.

[Ulzgoroth]

Originally Posted by Tomsdad

You better on GURPS than I am, do you know of the top of your head is you can suppress fire with NxM rounds? (even normally or for increased 'N' options in HT/TS)

I'm pretty sure that, as Fred Brackin's post suggests, you can suppress with it if and only if N is high enough to permit suppressive fire. M does not contribute to your ability to keep the air filled with lead.

[Tomsdad]

Originally Posted by Ulzgoroth

I'm pretty sure that, as Fred Brackin's post suggests, you can suppress with it if and only if N is high enough to permit suppressive fire. M does not contribute to your ability to keep the air filled with lead.

That's what I thought, hmm the issue here is shot pellets act differently at different times (to the limits of realistic spread of course).

[Ulzgoroth]

Originally Posted by Tomsdad

That's what I thought, hmm the issue here is shot pellets act differently at different times (to the limits of realistic spread of course).

Not sure what you mean here?

[Tomsdad]

Originally Posted by Ulzgoroth

Not sure what you mean here?

I guess I'm thinking sometimes that they act more like a single projectile and sometimes that act more like lots of projectiles. However I guess I'm just really getting caught up in unrealistic shot spread. Shot doesn't really spread enough to warrant treating it as lots of little bullets in terms of spray fire or suppression fire (i.e it's still discrete clumps of shots enough until you get to ranges that are really fringe for effective shotgun fire anyway), and it's only really worth distinguishing them from being one solid projectile at the point of impact.

That said how do you do spray fire for fully automatic shotguns, as it would seem to need ROF rules for spray as per normal to determine the effects on different targets, and then ROF shotgun rules for the individual targets as well.

i.e take the 6x9 Daewoo in HT shooting at 2 targets say 2 yards apart, ROF6 means I can use spraying fire (and I guess it would mean I'll lose 2 rounds moving 2 yards between targets as). BUt how doe the actual roll to hit each target work?

If I was just firing at the first target in isolation it would be 6x9 ROF54, but I can't use that here because I'm not going to fire all six shots at him, I don't know how many I hit him until I know my ROF bonus and I don't know my ROF bonus until I know how any shots are heading his way (and how many are heading towards the 2nd guy will depend on how many the first guy got) etc, etc, it seems to be circular problem.


Now of course it is a bit fringe (there aren't that many FA shotguns out there) but I couldn't find anything on the search on this.

Also given how effective spray is at allowing you to it multiple targets (or rather how difficult is to do it otherwise), it seems a bit odd that a ROF6 shotgun can do it pretty easily but a ROF3 (but up to 9 with fast firing so it's actually firing faster than the shotgun*) pistol is doing it with a -6 neg for each additional target, although I get the penalties for fast firing you're using the gun not as it was intended. Is this just a balancing act to stop everyone shooting multiple targets every second, is the fact that spray fire targets all have to be with a narrow arc, but rapid fire targets don't a contributing factor here? EDIT: and actually in TS targets for rapid fire do have to be in the same 30 degree angle as spray fire targets, further penalising RF in comparison to spray. So lets take a gun that can do both the FN FK 16 MOD (HT pg121).

Two targets 1 yard a part within 30 degrees etc, etc

FA fire with ROF9 I get +2 against the first target and the a possible bonus against the 2nd depending on how many time the first guy get hit and losing a round in the yard between them (and the Rcl on the 2nd target will be 3)

SA fire rapid strike using FF to get the same ROF9 (splitting it 4 and 5) only first target is -6 (Rapid Strike) -9 (Fast Fire) so -15, and rcl will be 3. The second target is -6 (Rapid Strike) -9 (Fast Fire) +1 (ROF5) so -14 but recoil will be 4.

SA not using FF is better its just -6 for each, which I actually prefer!


anyway I have **** all personal experience of firing guns so that may well be a factor here!

*i'm guessing the mechanical difference between the SA and FA mechanism is a factor her but I'm not seeing why, you're firing lots of bullets and adjusting the gun so they move towards different targets, is the number of times you pull the trigger (or fan the hammer or slide the pump) that much a factor on top of that?


EDIT: and while I can find references here that you don't use NxM to calculate spray fire is it stated anywhere officially? The main book only references the 'N' as the numbers of rounds fired for ammunition which is used up, but says "when resolving the attack multiply both together to get the effective ROF" for me assessing spray fire would fall under resolving the attack? Any way semantics aside apologies if this has been asked & answered in official errata or a developer posting "yeah it's like that guys".

[Jovus]

So, just as a silly idea, since shotguns were designed to make it easier to hit things like birds:

How about for purposes of counteracting negative SM only the bonus you get from using a shotgun is equal to the RoF using all nine pellets? Otherwise you use the RoF of the 'shots' you fired.

So, if you have a shotgun that's 3x9, and you're shooting at a SM -4 object, figure the bonus due to RoF as though you fired 27 shots, but do not increase past zero.

Then, if you shoot all three shells, treat your actual bonus as RoF 3, for +1. Those stack.

Hmm, I don't like that. It's clunky.


What about fractional recoil? Shotguns have Rcl 1/3 instead of 1. That means that on a roll that hits exactly, you hit with 3 pellets; MoS 1 means a hit with 6, MoS 2 means a hit with 9, etc. Are there any problems with that besides doing fractional math?

[Ulzgoroth]

For spraying and suppressive fire, the key thing is that you can't use your gun like a bullet-hose unless it acts like a bullet-hose.

A shotgun firing 3x9 is firing 3 blasts of pellets. There's more than enough independent shot going out to form a stream for spraying or suppressing fire, but the shot actually come in 3 pulses, not one stream. The issue isn't so much lack of lateral separation between shots as an excess of temporal separation.

If you were spraying fire with an automatic shotgun, you'd figure out how many rounds are directed at each target out of the N, then multiply that number by the M for the individual attacks. Similarly to what you'd do if you were using a rapid strike to fire some of your shells at one target and some at another.

(It also might not be appropriate to use the cumulative rcl penalty for subsequent targets, since rcl 1 on shotguns is a bit of a qualitative thing...)

[Mathulhu]

Spreading Fire and Auto shotguns firing NxM where N=6 and M=9


Assign shots per target from N.

A gets 2
Square 1 gets 1
Square 2 gets 1
B gets 2

These shots are then multiplied by M.

A gets 2x9 = 18
B gets 2x9 =18


I can't find an explicit mention that you can't split fire from the M portion of the attack but it makes sense.