[Pyramid 3/52] LT Armor Design: Mail vs Pi (Guns)

[DanHoward]

Originally Posted by Rupert

It's possible Myth Busters were using a harder alloy, perhaps?

Probably. They would likely have purchased the lead from a munitions supply shop along with the powder and other supplies. It isn't pure lead; it is an alloy of lead, tin and antimony, which is harder than pure lead but just as easy to melt and cast. I agree that pure lead should not have behaved like it did on that Mythbusters episode.

[Fred Brackin]

Originally Posted by DanHoward

Probably. They would likely have purchased the lead from a munitions supply shop along with the powder and other supplies. It isn't pure lead; it is an alloy of lead, tin and antimony, which is harder than pure lead but just as easy to melt and cast. I agree that pure lead should not have behaved like it did on that Mythbusters episode.

In the Old West episode "Unarmed and Unharmed". They were using .45 Long Colt cartridge revolvers. I doubt they handloaded the rounds. The bullets would have been whatever alloy that particular ammo company used.

That almost certainly would have been something other than pure lead. Of course, old gun users who did cast their own bullets may not have used pure lead either. A couple of times I read modern gun writers (or at least guys from only 30-40 years ago) discuss where to scavenge lead for hand-casting from and their preferrence seemed to be "linotype metal".

A quick Google turns up an 84% lead, 12% antimony and 4% tin recipe. People could easily heve been raiding old print shops for metal to melt down for several centuries before this one. Guns and movable type are about the same age.

There were also old tales about an early elephant hunter who had a 4 bore muzzleloader and he apparently used some kind of campfire alchemy involving mercury to harden his musket balls for greater pentration. No doubt the poisoned himself like most other people who fooled around with mercury. There's no telling where he learned the trick or how old it was either.

[Tomsdad]

Originally Posted by Sorenant

I was thinking less about passing right through the links and more in the line of the bullet "biting" into the links and transferring its energy on a small number of rings instead of getting deflected by a plate's curvature and also facing a solid mass of metal. Not unlike arrow/bolt vs mail/plate, I know mail was effective against such projectiles, but less so than plate, so my intuition was that a fantastic mail would be less effective than a fantastic plate in stopping a bullet.

Thing is that's what a piercing (small p) attack does on plate as well. Concentrates all it's force on a very small bit of plate and try and overwhelm its resistance to being penetrated.

In GURPS terms some arrow with heads designed for this count as P anyway (see the deadly spring in Pyramid and Bodkin points).

Now given the different construction of mail vs. plate, those different constructions failing might look different but it doing the same thing.

What not helping here is that when mail, plate and guns coincided historically even the best steel had to be pretty thick to stop bullets. As bullets got more energetic armour had to get thicker. Now with plate while there are some technical issues with making thicker plate in general it's construction meant you just made it thicker and thicker* increasing it resistance to penetration. Obviously weight becomes a factor! But with mail because of the way its constructed i.e the rings link (and move) you can't just keep making the rings thicker and thicker. What you can do of put multiple layers of mail on. But ultimately as per the article plate is more efficient at DR per weight in abstract.


Magical stuff like orriculum might well change all that. A metal resistant enough might well make bullet proof mail a thing. It will still be less efficient than plate in terms of DR per weight which means it will be worse than plate, but you have the advantage of it being flexible**! And if it can still do it's job worse is relative term.


FWIW the later articles with much harder materials allow for bullet proof flexible armour again with HT/UT scale, but it's still fundamentally little bits of armour mosaic-ed together onto a backing (some UT versions might do away with the backing I guess)


*and/or did stuff like angling. fluting, ribbing. All basically increasing the amount resistance via effective thickness and/or deflection and thus protection from incoming force without uniformly increasing the thickness of the plate. Mail can't really do all this (although it has it's own tricks).


**yes OK blunt trauma, but also no chinks, no gaps,

Originally Posted by Sorenant

On the other hand, just as you said, it's a magic material so it might just be strong like that.

pretty much

[DouglasCole]

Originally Posted by Tomsdad

In GURPS terms some arrow with heads designed for this count as P anyway (see the deadly spring in Pyramid and Bodkin points).

Note that this is just TDS repeating the canonical bodkin formulation. My overall impression was that the arrowheads which were forged and hardened (and there's a line repeated in - i think - one of Hardy's books about fines being leveled for improperly hardened arrowheads) as armor piercers did not suddenly count as high velocity, low momentum projectiles with dull points in real life. I get what pi vs imp is trying to do, but from what I understand about the lozenge-shaped or Type 16 warheads, they really should just cost a bunch and do (2) imp.

[Tomsdad]

Originally Posted by DouglasCole

Note that this is just TDS repeating the canonical bodkin formulation.

TBH I couldn't remember if bodkins doing Pi were in Character and LT so I was kind of hedging on that one ;-) !

Originally Posted by DouglasCole

My overall impression was that the arrowheads which were forged and hardened (and there's a line repeated in - i think - one of Hardy's books about fines being leveled for improperly hardened arrowheads) as armor piercers did not suddenly count as high velocity, low momentum projectiles with dull points in real life. I get what pi vs imp is trying to do, but from what I understand about the lozenge-shaped or Type 16 warheads, they really should just cost a bunch and do (2) imp.

I think at some points (i.e arrows) the difference between Pi++ and Imp as distinct different things kind of just breaks down.

I guess you could look at there arrow heads in relation to the Pi, Pi+ & Pi++ diameters in HT.

[DouglasCole]

Originally Posted by Tomsdad

TBH I couldn't remember if bodkins doing Pi were in Character and LT so I was kind of hedging on that one ;-) !



I think at some points (i.e arrows) the difference between Pi++ and Imp as distinct different things kind of just breaks down.

I guess you could look at there arrow heads in relation to the Pi, Pi+ & Pi++ diameters in HT.

Many war arrows are a half inch in diameter with just the shaft (pi+) and even some of the more compact Type 16 arrowheads are roughly double that including the barbs (which I believe have evidence of being hardened. That sort of evidence tends to be somewhat sketchy (in the 'absence of evidence is not evidence of absence' sense) due to the hardened jackets being the stuff that corrodes away first.

Anyway, some of the warheads would qualify for pi++ or imp; most hunting arrows would too.

[Anthony]

Originally Posted by Tomsdad

I think at some points (i.e arrows) the difference between Pi++ and Imp as distinct different things kind of just breaks down.

They're distinct penetration mechanics, but it's a distinction that only matters on targets soft enough to be cut, which is generally not the case for metal armors.

[Varyon]

Originally Posted by Tomsdad

I think at some points (i.e arrows) the difference between Pi++ and Imp as distinct different things kind of just breaks down.

The way I understand it, there are basically three different wounding modes covered by Imp and Pi. One is having a tiny sharp point enter the target, then using that beachhead to let the wider parts of the weapon enter by pushing material aside. Spears made entirely of wood, estocs, and similar use this method. I think armor piercing rifle rounds do as well, but once they're in their high velocity, low weight, and tendency to tumble make them behave more like option 3 (see later). The second is similar, except the wider parts of the projectile are thin and sharp and actually cut into the target rather than just pushing material aside. This is what you see with typical spears and arrows, as well as swords. The third option is to have a relatively blunt object flung at the target at such a high velocity it goes through it, crushing a path through whatever is in the way. This is the way bullets work.

In terms of armor penetration, the first is Imp, the second is sort of like an Imp/Cut fusion, and the third is Pi. For DR that differentiates, if you want to have really high resolution, the second would probably give DR roughly halfway between what the target has against Imp and what it has against Cut (if it somehow has better DR against Imp than Cut, just treat it as Cut). Note this is probably is only appropriate if the sharp edges are fairly wide (enough so that if they were blunt the projectile would have trouble pushing material aside to get past the armor).

In terms of wounding, the first and third are fairly similar, primarily involving a wound channel that consists of a lot of crushed tissue. The second is a bit different, as the wound channel is likely wider but thinner, and also consists more of cut tissue than crushed tissue. All three rely more on going deep to hit something important than on outright wrecking the body, so all three would be susceptible to reduction from IT:Unliving and IT:Homogeneous. When IT:DR and Vulnerability are involved, however, they could be treated differently. IT:DR/Vulnerability to Cutting (representing tissue that's harder or easier to cut) would probably apply normally to the second option. IT:DR/Vulnerability to Imp (representing tissue that's harder or easier to punch through with a sharp tip) would probably apply to the first and second, while IT:DR/Vulnerability to Cr (representing tissue that is rarely or easily crushed/broken) could probably apply to the first and third. You could also have a general IT:DR/Vulnerability to Imp and Pi (representing redundant/resilient internal organs, or those particularly susceptible to disruption) that would apply to all three, and would basically be the IT:DR/Vulnerability equivalent of the Living-Unliving-Homogeneous progression. Pricing would be difficult to work out, but then pricing for limited IT:DR/Vulnerability is kind of already a bit broken, particularly when comparing to Unliving/Homogeneous (IIRC, IT:DR that would protect against one of Imp or Pi is around twice as expensive as equivalent protection from Unliving, or Homogeneous if you take out the price for its add-ons).

[DanHoward]

Originally Posted by DouglasCole

Many war arrows are a half inch in diameter with just the shaft (pi+) and even some of the more compact Type 16 arrowheads are roughly double that including the barbs (which I believe have evidence of being hardened. That sort of evidence tends to be somewhat sketchy (in the 'absence of evidence is not evidence of absence' sense) due to the hardened jackets being the stuff that corrodes away first.

The Type 16, not the bodkin, was the armour piercer.

http://forums.sjgames.com/showpost.p...4&postcount=15

http://forums.sjgames.com/showthread.php?t=33436

[RyanW]

Originally Posted by Anthony

Realistically, people make bulletproof steel plates and as far as I can tell no-one even tries to make bulletproof mail, and there's probably a reason for that, though I'm not immediately sure what it is.

They tried making mail for protection in WWI, but found that the bullet tended to push shattered fragments of links into the wearer. They did find that if draped rather than worn close to the skin, it stopped fragments pretty well. There are some examples of face masks for tankers.