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

[Sorenant]

The Mail construction gives -2 or -20%, whichever is worse, to DR vs Crushing but it provides full protection against Piercing.
In a fantasy setting it would be possible to make an orichalcum mail with DR 18, enough to be considered proofed against modern (non-AP) rifles. It's fantasy, so a lot of logic is out of the windows, but is it intended? Would such an armor be like the mithril shirt from LotR, with each ring so small it looks like a fabric and has no apparent holes for a bullet to pass through?

[Dustin]

Even very ordinary mail doesn't have holes large enough for most bullets to pass cleanly through. They will have to break some links, just like a blade would.

Here's some mail with a ruler for scale
https://i.ebayimg.com/images/g/5vkAA...WEu/s-l400.jpg

So yes, for a magical material that's more than twice as strong as TL7 steel, why not DR 18?

[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.

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

[Dustin]

Originally Posted by Sorenant

my intuition was that a fantastic mail would be less effective than a fantastic plate in stopping a bullet.

For a given weight of metal, you're right. Using those rules (Pyramid 3/52), the weight factor of plate (0.8) vs mail (0.9) means that plate armor of the same mass provides 12.5% greater DR than mail.

[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.

[Sorenant]

Originally Posted by Dustin

For a given weight of metal, you're right. Using those rules (Pyramid 3/52), the weight factor of plate (0.8) vs mail (0.9) means that plate armor of the same mass provides 12.5% greater DR than mail.

Mail CW in the article seems rather low, a DR 3/1* mail in LT weights half as much a plate of equivalent DR. Playing with the values a little, I found that the following values gives results slightly closer to LT: Plate CW 0.65 and CC 5; Mail CW 0.975 and CC 1.6; Scale CW 1.3 and CC 0.8.
This gives: DR 3 plate costs $1023.75 and weights 8.19 lbs, DR 3/1* mail costs $491.4 and weights 12.285 lbs, DR 3/2* scale costs $327.6 and weights 16.38. Scaling in LT is not linear, so higher DR version using this will result in generally light and cheaper gear.
It's not related to the question at hand but I wanted to share the idea.

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.

As far as I know, bulletproof plates involves plackarts which acts like spaced armor and the curvature aided in deflecting the bullet. I don't think a mail would have those benefits, but I'm not professional to say anything with confidence.

[johndallman]

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.

Making plates is easier, with modern manufacturing.

[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.

[DanHoward]

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.

GURPS has separate blunt trauma rules for that.

[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