160 LB longbow v 5MM breastplate armor

Came across this video and thought it interesting and valid - 160 LB longbow v 5MM breastplate armor


That video has me asking if an arrow will go thru soft body armor…

Bulletproof Vest vs Crossbow and Compound Bow

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That’s amazing, I would not have predicted that, I thought a hardened arrow would zip right through sheet metal. thanks for posting. I am guessing it is 0.5mm. 5mm would be almost a quarter of an inch thick.

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Kinda like in the Dune book series - they could get through the force field “armor” with a knife because it was slow.

I believe a lot of cross-bows could penetrate armor because they had much higher velocity (thus energy like a bullet)

That would be a heavy foil at 0.0197" thick or between 26 gauge and 25 gauge sheet.

It’s apparently 2.5mm thick in the central region of the plate (between 13 gauge and 12 gauge sheet steel):

A steel or ceramic trauma plate would probably stop an arrow nicely. But soft armor is vulnerable to something as pointed as an arrowhead (or knife).

Think of it like this. You have the kinetic energy of the entire length and weight of the arrow’s mass impacting on the steel tip of the bodkin arrow point. A typical medieval arrow weighs 75 grams. Your typical .45 bullet is 15 grams (230 grain). Then speed comes into play. A typical .45 pistol bullet travels at 830 feet per second. Arrows typically travel between 225 to 350 feet per second depending upon draw weight.

35 to 69 newtons 75 gram arrow at 10 yards at 330 fps

43 to 87 newtons 15 gram bullet at 10 yards at 830 fps

BUT - a bullet mushrooms and the force spreads out over an area of the size of about a dime. The arrow places all that force onto the tiny steel point. The impact energy of the bullet and the arrow are similar, but the energy diffusion is different and what matters for penetration.

This is why kevlar is great for spreading out the energy of a bullet as it pancakes on the armor, but an arrow or even an ice pick can go right through.

Don’t ever point this out to a woman wearing stiletto heels, but the PSI on a pointed heel can exceed the PSI exerted by a shark bite ( up to 7000 PSI ) because all that force comes down on one tiny point.

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Having designed and sewn soft armor professionally before, soft armor will “wrap” around the bullet or impact to prevent penetration, though there’s a nasty backface deformation that occurs because the bullet essentially becomes a small sledgehammer. Severe bruising is quite common - but you aren’t bleeding. The reason that broadpoint arrow didn’t penetrate was because the surface area of the impact was so great. A bodkin or pointed arrow would probably penetrate (surface area and velocity). Knifes with large profiles will do poorly against soft armor as the greater the impact surface area, the more energy is spread over the -usually- 16 layers of fabric.

Soft armor is made by layering numerous sheets of “kevlar” (numerous flavors and laminates) at various angles depending on weave (warp and weft direction change characteristics) to create a material that is very slash/tear resistant. Rifle rounds generally penetrate because they’re going sometimes 3 times the speed of a pistol round (as is the case with the 5.56/.223 round - 3000 FPS). You also find “barrier blind” or similar ammo with hardened “penetraters” (usually a hardened steel core) that penetrate such armor even more easily. The whole point of something like the P90 (for the stargate fans out there) was to shoot a round that could be fired from a pistol that had mild armor penetrating capabilities (SS109 rounds). The intent was for rear echelon NATO troops to be able to defend themselves against Russians wearing soft armor jumping behind the lines. To this end, the Russians had some fairly interesting pistol and rifle rounds that were sabots and shot tiny steel darts going very fast to get through NATO armor.


War Hammers: one side with a pointed spike or maces with spikes were hell on armor … but not as agile as a sword and you had to be up close and personal.

Cross bows took advanatge of the fact kinetic energy goes up exponentially with speed this hit harder with a lighter arrow and point was specifically made for armor.

That and much easier to train than being a skilled bowman, but didn’t have range on rapidity with which and archer could shoot. Largest long bow I’ve every pulled was 150#, arms were shaking … my accuracy wouldn’t amount to much.

[quote=“matthshooter, post:9, topic:62260”]
[/quote] Did you mean a broadhead arrowhead or a bodkin arrowhead? A broadhead arrow is designed to create severe laceration - a cut wound track - typically for hunting game. A bodkin point is to penetrate armor.

Left to right - Bodkins, Broadheads, warhammer. The outter two are specifically for armor penetration. Center is typically for hunting with less dramatic smaller versions used against unarmed troops.

Meant broadhead in reference to the soft armor shooting video - that would definitely not go through soft armor, but a narrow point like a bodkin would definitely do so.

I thought the “end of armor” was:

  1. Crossbow (sometimes with winch to cock). Less muscle, less talent, almost any peasant could fire with just a little practice (as opposed to years of training to be an effective longbowman).

Yes, rate of fire was lower, but one shot impact per armored individual stood a high chance of ending the battle.

  1. Quarrel/Bolt with BLUNT tip that had a small bit of Beeswax on the tip.

The wax “grips” during the microseconds of impact on curved armor and transfers energy rather than just glancing off. Result is an armor piercing shot, in all but the worst placement/angle. Center mass shots worked very well.

None of that was in the video…??

Is that info about crossbow+blunt+wax historically accurate? Or did I just read an unfounded rumor somewhere?

One suspects that on the other end of things the ever-increasing mass of armor required to defend against new threats made it sufficiently impractical for the user that it was discarded without needing to be defeated in combat.

Exactly! The threats outweighed the weight / practicality of the armor at some point. (point - ha ha)


The inexpensive stilletto triangulate bladed dagger was the peasant’s answer to armor. Made from hardened brass or broken fencing blades, it was designed to be used at the weak points of armor. The blade was meant to make a wide rough puncture wound. The person in heavy armor would bleed out. Once limp from the wound it’d be close to impossible to get the victim out of their heavy armor to staunch the bleeding. It was likewise impossible to get a branding iron to the wound to cauterize it shut. Sometimes the top of the blade had notches filed into it. Some initially thought the notches were made to make the blade easy to snap off in the wound but this is a false assumption. The notches were added to get the blade stuck in chainmail which was often used to try to secure weak points in armor. Then trying to remove the dagger would make the wound far more severe killing the victim faster.

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All of this information would have made high-school history classes much more interesting. This is fascinating!