(Basic Set; Low Tech) Slinging things

[Dalillama]

Originally Posted by Fred Brackin

A thrown baseball has more momentum than even rifle bullets but I know which "impacts" I'd rate as more survivable.

The impact of the baseball is spread over several square inches, vs the bullet that's usually about 1/3 inch in diameter

[Fred Brackin]

Originally Posted by Dalillama

The impact of the baseball is spread over several square inches, vs the bullet that's usually about 1/3 inch in diameter

Yes, but it's the fact that Gurps (and apparently the real world's) _damage_ mechanism is based on kinetic energy (velocity squared time mass) rather than momentum (mass times velocity) that's making the real difference.

[Varyon]

Originally Posted by Dalillama

The impact of the baseball is spread over several square inches, vs the bullet that's usually about 1/3 inch in diameter

Even so, I think I'd rather be hit with something the weight and velocity of a baseball and the shape and size of a rifle bullet than be hit with something the weight and velocity of a rifle bullet and the shape and size of a baseball. I might consult Cole's ballistics spreadsheet later to see how the two would compare in GURPS. Granted, I'd rather not get hit by either...

[Anthony]

The reference to slings being equivalent to a .44 magnum I find is this. Using the numbers in that article (100 mph, 50g) it's about a 3x heavier projectile at 1/10 the speed, which is... not even close.

A less clickbait-ey study I found is this.

[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.

[jacobmuller]

Originally Posted by Anthony

A less clickbait-ey study I found is this.

Thank you, everyone.
I was wondering how big a difference lead bullets would make and it's in there
And on rereading basic set
GURPS has it covered
I can switch my brain into sleep mode again.

[DanHoward]

Thom Richardson did extensive testing with reconstructions of ancient slings*. He used projectiles made from lead and stone and no matter the material, weight, or shape, the velocity (3m from point of release) was very similar. The slowest was 30.3m/s and the fastest was 31.2m/s, which is around 110km/h.

Average range for stones weighing 45-75 g was 90 m, the range for stones weighing 80-85 g was 84 m, and the range for stones weighing 85-160 g was 82 m. Two types of lead shot were tested; one was spherical (‘ball’) and the other was more almond shaped (‘shot’). The 38 g balls averaged 114 m and the 100 g balls averaged 107 m. The 40 g shot (29 x 18 x 13 mm) travelled 145 m on average and the 85 g shot (39 x 22 x 16 mm) averaged 120 m. Overall, lead outranged stone by about 50%.

Roman glandes weighed up to 60g (most were closer to 30g) so the 85g one is too heavy, but even this one would only deliver around 41J of kinetic energy at 3 meters from the point of release.


* T. Richardson, "The ballistics of the sling", Royal Armouries Yearbook, Vol. 3, (Leeds: Royal Armouries, 1998).

[Anthony]

Originally Posted by DanHoward

Thom Richardson did extensive testing with reconstructions of ancient slings*.

The link I gave actually mentions that study (p.45 and 51-53); there is reason to think his measurement method underestimated velocities, though certainly not by enough to justify any of the more dramatic claims about slings.

[Rasna]

Originally Posted by DanHoward

Thom Richardson did extensive testing with reconstructions of ancient slings*. He used projectiles made from lead and stone and no matter the material, weight, or shape, the velocity (3m from point of release) was very similar. The slowest was 30.3m/s and the fastest was 31.2m/s, which is around 110km/h.

Average range for stones weighing 45-75 g was 90 m, the range for stones weighing 80-85 g was 84 m, and the range for stones weighing 85-160 g was 82 m. Two types of lead shot were tested; one was spherical (‘ball’) and the other was more almond shaped (‘shot’). The 38 g balls averaged 114 m and the 100 g balls averaged 107 m. The 40 g shot (29 x 18 x 13 mm) travelled 145 m on average and the 85 g shot (39 x 22 x 16 mm) averaged 120 m. Overall, lead outranged stone by about 50%.

Roman glandes weighed up to 60g (most were closer to 30g) so the 85g one is too heavy, but even this one would only deliver around 41J of kinetic energy at 3 meters from the point of release.


* T. Richardson, "The ballistics of the sling", Royal Armouries Yearbook, Vol. 3, (Leeds: Royal Armouries, 1998).

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.

[Pursuivant]

Originally Posted by Anthony

The link I gave actually mentions that study (p.45 and 51-53); there is reason to think his measurement method underestimated velocities, though certainly not by enough to justify any of the more dramatic claims about slings.

It might be possible to estimate maximum sling velocity by comparing it to maximum speeds that a pitcher can get when hurling a baseball. Physiologically, a fastball tops out at ~100 mph. Other throwing actions generate about the same relative KE at launch.

Assuming that a slinger can use basically the same throwing motion but use a sling as a lever, that would get you theoretical maximum sling velocities.

Once you've got that data, you can then use ballistics to work out theoretical ranges and KE for various sling missiles.

That would allow simpler calculations for range and damage when a character hurls an odd-sized missile. ("How far can I hurl an 8 oz. grenade using a sling?")