Medieval 1250 lb Great Horn Composite Crossbow vs Breastplate

Today, I'm going to test a so-called large arm breast. The arm breast has a pull weight of about 560 kg and shoots 280 g of heavy bolts. Large crossbows can already be found in pictorial sources from the early 14th century and appear frequently in 15th century inventories. The bolts are around 650 mm long and their weight varies between 275 and 285 g. The shape of the points corresponds to that of the surviving originals. While the two flat pyramidal heads are not hardened and tempered and have a hardness of around 200 Vickers, the third head is hardened to around 440 Vickers or just under 52 Rockwell. The target consists of a ballistic gel dummy with textile armor. Above this is a two-part breastplate. The infantry breastplate is based on originals from around 1470 and is 2 mm thick, which is in the middle of the usual thicknesses of the time. The weight is 3.9 kg. The plate is made of mild steel and has a hardness of around 110 Vickers. For safety reasons, the crossbow is spanned with a modern spanning device. As with all the other tests carried out, the shooting distance is 12 m. Although the material thickness of the wooden bolt shaft was more than 20 mm, the oscillation after release is clearly visible. The velocity for the three bolts was around 52 m per second or 170 ft per second. The maximum possible shooting range was shown in an earlier video. It is 250 to 300 m or 270 to 330 yards for this crossbow. The kinetic energy was 370 J for the 275 g bolt and 380 J for the 285 g bolt with a hardened pyramidal head. The performance of armor depends on its material thickness, its shape and the degree of hardness as well as the energy of the hit. The performance of bolt or arrow heads in turn depends on their weight, their shape, the degree of hardness, the angle of impact and the speed at which they are shot. All three bolts penetrated the 2 mm thick breastplate. The heads left cross-shaped cuts and folded the plate inwards until the rectangular cross-section of 21 by 22 and 18 by 23 mm. The penetration depths ranged between 36 and 38 mm. On the textile doublet, consisting of several layers of linen and a filling of wool, only damage to the outer layer could be observed. The ballistic gel torso shows no signs of injury. In conclusion, the breastplate has done its job well. Even though it has suffered massive damage, there are no open wounds. However, the force of the impact and the associated trauma values, which could lead to fractures or blunt, internal injuries, should not be underestimated.