Re: Slings, realistic physics, The Deadly Spring
 

I imagine that when you get down to the details even "universal" human features like how the joints articulate and where muscles attach might vary and screw with the end results.
My arm bones are exceptionally thick and don't allow full or hyper-extension. So I can never get good at holding bows pulled back.

Re: Slings, realistic physics, The Deadly Spring
 

Sure.

But it makes more sense to class slings with bows and crossbows in performance than it does to class them with short-ranged thrown weapons. It doesn't mess too badly with anyone's suspension of disbelief to have thrown weapons massively outpenetrate longer ranged missile weapons, as that result was also expected in reality.

Granted, GURPS overstates the difference at high ST levels, but I think I can live with that for the time being. .357 Magnum slings, however, are disconcerting.

Re: Slings, realistic physics, The Deadly Spring
 

Indeed.

Of course, there are other researchers achieving velocities of at least 50% and sometimes 60% higher than he is, even with the same sling and same ammunition. Those are not even master slingers, but simply young people in decent condition who train for several weeks. See Eric T. Skov, Experimentation in Sling Weaponry.

Richardson himself admits that his ranges are below what most other tests yield and acknowledges that he might be using inferior technique.

So I'd be inclined to believe that his results are not representative of the sling as a weapon of war, even if the sling he used may have been used in warfare. It is, of course, far safer and more comfortable for a novice to avoid full-power launches in favour of more leisurely throws.

This also matches results that people from cultures that use the sling as a toy and shepherding tool achieve. If they are not specificallly instructed otherwise, they'll use a sling, ammunition and technique which are optimised for accuracy at short ranges and which do not reach very far. That's good for scaring wolves, killing small game and anything else these cultures would actually use the sling for.

However, just like most warbows are not designed or used in the same way as toy bows or even bows for hunting small game, this does not tell us much about the use of war slings. I'd expect them to at least match the velocity achieved by Skov and probably exceed it. Indeed, the ranges confirmed by the small fraternity of enthusiastic slingers indicate that much higher velocities must be achievable with training. If you can launch a 40-50g stone more than 450m, an equally skilled user with a lead glans can achieve significantly more impressive velocities and ranges than Richardson. There's no way to come close to that range with an initial velocity around 30m/s, not unless you suspend gravity and air resistance.

Unfortunately, no one among the very small fraternity of skilled slingers has as yet performed sufficiently exhaustive testing with slings designed to kill humans at long ranges, probably because that's not a competative sport. Some of the best slingers for achieving long casts are competing in an event where only stones may be used, for example. They'd need to get used to a new type of sling and a new shape of projectile to demonstrate the range and velocities achivable with replicas of the archeological lead glandes. Not to mention that lead glandes, unlike stones, are not easily visible in flight.

As a result, we lack reliable velocity data for people who actually can sling with anything approaching the power to be useful on a battlefield. Extrapolating from the distance of world records, does, however, indicate that velocities up to 90m/s may be achievable. As with bows, the ST of the user is important more for how heavy a projectile can be launched to those speeds than for determining the velocity itself. With slings, however, that's not determined primarily by material properties and design principles (although these are important), they are skill dependant. That argues that untrained use of the Sling ought to suffer damage penalties and that Perks to improve performance, much like Strongbow, ought to be available.

Aside from other considerations, it seems to me that 28g-40g glandes are probably more economical than effective, with heavier glandes being much more likely to wound and kill humans and larger animals. A 36g glans can be lethal, yes, but a more important consideration is that you can obtain more of them for the same amount of lead than you can make of more lethal 62g or 100-120g ones.

The reason we find a lot of those small glandes is that in most historical warfare, something that did 1d(0.5) cr was a scary enough weapon and it was better to put more of those in the air than try for 1d+2 cr at the cost of spending x4 as much and having to carry x4 as heavy ammunition. Adventurers in GURPS may feel differently.

Re: Slings, realistic physics, The Deadly Spring
 

We do already have proposed options that do a bit about the sw/thr damage issue, remember. Not from a 'do the physics' perspective, but still, any mismatch will be smaller.

Re: Slings, realistic physics, The Deadly Spring
 

Even for those of us who are fine with the standard GURPS damage tables for melee weapons, the sling at ST 14 generates 2d pi damage. Without a reasonable AD, such as the aforementioned (.5), I think that creates a bit of an issue with suspension of disbelief. Sure, ST 14 is very strong, but that damage is 7 points of penetration...that'll get through all chainmail ever made. I just don't see that happening. With the (.5) AD tacked on, this doesn't happen. I have less issue with the sling going through leather, though even that is probably unlikely.

But, at the end of the day, either these weapons were useful or they weren't. We know they were used. We also know armor was used. And more importantly, in play we know that PCs and enemies will wear armor (perhaps even ahistorical levels of armor), and there's frankly no good gameplay reason to nerf muscle powered weapons down to no effective damage.

Edit: Here's a thought, maybe rather than a straight up (.5) AD, we apply the "edge protection" rule to sling bullets. Basically, if they can't penetrate, they can still do crushing damage, which I find much more believable.

Re: Slings, realistic physics, The Deadly Spring
 

According to models designed by the US Armed Forces to model bullet penetration, even the world records of slinging with a 28g to 51g bullets would not have penetrated winter clothing at point blank range. GURPS assumes 28g sling ammunition, which I'm comfortable saying will never penetrate DR 1 armour at human ST scales, except on a critical hit.

Sling damage is not pi and cannot be modelled as pi. It's crushing damage and while it can be lethal to unarmoured people, for the most part, like arrows, even a solid hit will tend to wound and not kill a human.

Re: Slings, realistic physics, The Deadly Spring
 

It's not clear why slings in 4e do piercing damage to start with, the evidence for slingers targeting eyes or vitals is pretty thin, and in general it appears that slings killed without making holes in people (the enemy dies from the blow of the stone without the loss of any blood).

Re: Slings, realistic physics, The Deadly Spring
 

I'd be inclined to call it crushing and then be done with it then in my games. Piercing for slings is probably the strange part. And I have no trouble believing that a ST 14 person firing a sling stone for 7 damage will do some damage to a guy in chainmail. Maybe not 5 damage, but 3 for sure.

Re: Slings, realistic physics, The Deadly Spring
 

That's nearly a broken arm covered in metal armor. Now that seems a might silly for any rock slung by humans not named David.

Re: Slings, realistic physics, The Deadly Spring
 

I think a (.5) AD solves that nicely (because I do not disagree). Alternately, slings could be sw-2 damage or something. I tend to prefer the (.5) AD for stones and maybe lead shot.

If it's pi, ironically, the metal armor does better--DR 4 instead of 2.