(Basic Set; Low Tech) Slinging things

[Fred Brackin]

Originally Posted by Varyon

Stronger characters should be able to propel the same bullet faster, at least up to a point. .

It's is so limited a point that doing the math for it is not a good use of your time.

The sling's end is held by the end of the user's arm and the increase in velocity of the projectile can be no more than the increase in velocity of the user's arm. Unless your giants move at blur speed they won't be pushing anything at supersonic speeds.

[Varyon]

Originally Posted by Fred Brackin

It's is so limited a point that doing the math for it is not a good use of your time.

The sling's end is held by the end of the user's arm and the increase in velocity of the projectile can be no more than the increase in velocity of the user's arm. Unless your giants move at blur speed they won't be pushing anything at supersonic speeds.

If the sling couldn't move any faster than the hand, there would be no benefit to using a sling over just throwing something by hand. The sling acts as a lever (hence swing damage), increasing force and velocity - and whips demonstrate a human can indeed propel a lever quickly enough that the end of it breaks the sound barrier (and you need superhuman strength to have enough damage to break the sound barrier to start with, for a sling). I calculated you need around 7d for a typical glandes to break the speed of sound. I believe the LTC2 guidelines for larger weapons have the damage adds scale with the character's linear dimension - so SM+2 would be sw+2, SM+3 would be sw+3, SM+4 would be sw+5, etc. (it may be you'd need to increase the size of the projectile as well to see these gains, but seeing as that calls for a still-higher damage to break the sound barrier, we'll ignore it here). For SM+2, you would need ST 37 or ST 38 to reach 7d pi, which is achievable - average SM+2 ST would be around 25 (5 yards tall, rather than the 2 yards of SM+0's ST 10), so that means you'd be roughly at the equivalent of ST 15. You've also got a lever that's around 2.5x as long as on a typical sling.

Is that long enough to be able to break the sound barrier? Probably not, honestly, but if we're going for strict realism, we'd need to remake the ST-based damage table anyway. It's arguably not fair that a rifle bullet can't get past a speed-activated shield, but a sling bullet of the same weight and power can, so backcalculating the velocity of the latter can give you the breakpoint where it will be blocked. And, honestly, what I worked up does the math for the GM - all he or she will need to do now is work out what "speed limit" will be in play for the shields, divide my values by 340, and multiply by the new speed limit.

[Anthony]

Originally Posted by Varyon

Stronger characters should be able to propel the same bullet faster, at least up to a point.

It's a very limited point. The basic issue is that the amount of force muscle can apply varies with how fast it's contracting, so mostly the way you get more speed out of a sling is by making the sling longer (which makes it harder to control).

[jacobmuller]

LTC2 TQ
Formula = awesome.
Ballpark velocities using bullet weights that match BL: am I right that ST7, 0.05lb, Sw 1d-2, would be about 25m/s; ST10, 0.1lb, Sw 1d, 30m/s? Seem rather slow.
If those are right, then all the way up at ST30, 0.9lb, it's still under 100m/s, but using a 3lb, $30 sling. It's TL10. Old tech is cheap - the basic sling would be $5.
PS crushing damage would be nice vs high tech anti pi armor. Anyone know offhand what damage a 40mm grenade does inside the safe range, ie pi or cr?

[Varyon]

Originally Posted by jacobmuller

Ballpark velocities using bullet weights that match BL: am I right that ST7, 0.05lb, Sw 1d-2, would be about 25m/s; ST10, 0.1lb, Sw 1d, 30m/s? Seem rather slow.

Changing the weight of the bullet has a lot of follow-on effects, like changing the cross-sectional area (because the bullet is now larger). I think if we assume constant penetration (GURPS damage) the multiplier for velocity would be 1/(W^0.4), where W is the multiplier for weight (although honestly, you could probably ignore the change in cross section, and just use 1/W^0.5). So, doubling the weight means around 75% velocity. 1d+1, or 4.5 (what you get with ST 10 and a dense projectile - note that gets a +1 to damage) would be 62.2 m/s with a 0.05 lb projectile, so it becomes around 46.6 m/s for a 0.1 lb projectile. Note those are 139 mph and 104 mph respectively.

Originally Posted by jacobmuller

PS crushing damage would be nice vs high tech anti pi armor.

Tbone has some collision rules as part of GULLIVER that I think are fairly realistic and could be used here, but IIRC those are a bit hairy to use. GURPS would say a 0.1 lb projectile moving at ~Move 50 (100 mph) would deal between roughly 0.5d cr and 1.85d (call it 2d) cr, depending on if it counts as Living, Unliving, or Homogenous. You may be able to justify up to x2 on account of it being a hard, unyielding object, but I don't think that works outside of immovable surfaces.

Of course, an easier way if you're comfortable waving your hands a bit is to allow characters to use projectiles that are specifically shaped not to penetrate like pi but are the same weight; this results in only dealing sw cr, and you can estimate velocity as equal to what it would have had were it a pi bullet.

[jacobmuller]

If a 40mm grenade is 1lb at 75m/s - 4d6?
Is it Crushing or Piercing damage?
A Brown Bess is .75", 1.5oz at around 450m/s, and High Tech gives it as 4d+2 pi++.
Basic sling was 1d6+1 pi dam if ST10 and that might be around 1oz at 50m/s.
?Piercing is focused Crushing? Did bullets go Crushing damage in 3e?
Edit 3e bullets were Cr. Pi is Cr at higher velocity.
Anybody know the cut off velocity for the switch from Cr to Pi?
Golf ball, 40mm, 2oz, 120mph...
I like Pi slings but Cr seems to better fit the stats.

[jacobmuller]

Originally Posted by Fred Brackin

I would prefer that slings did CR

On looking at the stats, your preference seems logical. Not as much fun as a troll chucking a 4d pi++ rock, but maybe that makes it a genre choice

[Fred Brackin]

Originally Posted by jacobmuller

On looking at the stats, your preference seems logical. Not as much fun as a troll chucking a 4d pi++ rock, but maybe that makes it a genre choice

ST35 Trolls who use missile weapons definitely says something about what genre you're playing in. :)

[jason taylor]

Originally Posted by Rasna

I suspect that the skill of the slinger is crucial to determine not only how much the shot is accurate, but also how far the shot can go. Slingers in Roman army regularly practiced slinging to targets positioned at 183 m away from them. Ranges between 200 m and 240 m were recorder as reached by skilled slingers using pebbles as shots by both Korfmann (1973) and Stout (1977).

Also, slingshots could be very heavy, up to about half a kilo. The surviving flint slingshots from the siege of Lachish (701 BC) were all quite heavy, with an average weight of 263.87 grams and the heaviest of them weighting 387.5 grams. Since shots weighting about 30-40 grams were sufficient to inflict a stopping and potentially lethal injury to an unarmoured opponent, a slingshot weighting up to ten times more was very likely something capable to wound well-armoured opponents at the expense of range, accuracy and the quantity of ammos that a slinger could carry.

Be careful with that one. In English language a slingshot refers to the children's toy thingy with two forked sticks which is probably more accurate but hasn't enough impact to be a weapon except against small game. A sling is the spinning round the head thingy. A lot of Americans who have not researched the matter get confused.

I remember at least one time someone asked how David could have killed a professional duelist. Of course there is nothing unusual about the whole story except Goliath's size which was within possibility for a human with a growth disorder. As long as you remember that David was using a sling not a slingshot and he was probably as used to it as people in American small towns are used to firearms.

[jason taylor]

Originally Posted by Rupert

I do not think sling are under-rated by GURPS at all.

With lead bullets they out-range a short bow and have the same maximum range as a regular bow or longbow. They have the same rate of fire. The sling has a very low MinST, so just about everyone can use it effectively. Base damage is higher than that of bows, and even comparing injury to unarmoured torsos a sling beats a short bow, and is about the same as a regular bow. Longbows and composite bows are better than slings at injuring unarmoured locations that take impaling's damage multiplier.

You can stuff a sling into your pocket or wrap it around an arm or your waist whereas a bow is always an ungainly bent stick, and the sling and its ammo are lighter than bow and arrow. The sling and bullets are also cheaper, and in a pinch or for hunting small game you can just use stones for ammo and save your bullets for more important targets.

Slings really have only one disadvantage in the Basic Set - lower accuracy. If using the optional rules for harsh realism in Low-Tech they gain in relative accuracy. The change in damage type is probably a wash for slings - crushing can't be aimed at the eyes or vitals (though is using Martial Arts they can strike the vitals but not for extra damage), but they gain better blunt trauma and can cause knockback.

Then there's the Staff Sling, which trades wieldiness (it's as clumsy as a bow) for more range than a bow, more damage, and more accuracy.

I think that slings in GURPS are actually really good weapons (aside from poor accuracy) and that it's not the game that under-rates them, but rather the players. If you want to educate them on the wonder of slings, have a unit of ogre slingers exploit that lovely swing damage and don't forget that at shorter ranges slings can be used to hurl Molotovs and the like.

I for a long time wondered if heavy infantry didn't sometimes use slings as small arms. They probably did although an inexpert man couldn't aim a sling (most infantry ranged weapons are fired at To Whom It May Concern anyway). There were few occasions to use them in a shield wall however.