Saw the 7,000 man terracotta army in China, circa 210 BC, 2014 update on PBS, Emperor's Ghost Army. It had a nice feature on the crossbows. They are still digging up the site. One crossbow model unearthed in 2015 was 2/3 the length of an English long bow and was figured it could hit something 9 football fields away, 900 yards. No idea of the accuracy. Most of the wood parts that are dug up are rotted and not able to be used. The metal parts survived being buried in the dirt pretty good.
The bow and the stock were two separate pieces. The 3 big features on the stock was the gun like trigger, which was mass produced, made of high quality cast metal, some kind of bronze. That automatically made any crossbow easy to learn how to use it, and easy to operate it accurately and quickly. The end of the stock was slotted so a bow could easily be tied to it by almost anyone. You probably only did that wrong once. It was simple wood working to fit the trigger mechanism and notch the end of the stock, which made the stocks easy to mass produce. The bows required more skill to put together but could be done by a different group of workers.
Because they used bamboo for the arrow shafts, the arrow heads were very interesting. The actual point was a elongated solid pyramid, either 3 or 4 sides. The sides were slightly curved and ground flat on a grinder. Attached to the point was a 7 inch metal shaft. I imagine this added to the weight and impact of the arrow head, improving its penetrability, though it might not have been designed for that. The metal shaft was placed inside the bamboo tube (arrow body) and tied in place. Maybe they even had some kind of metal to wood glue.
The trick was in attaching the point to the shaft. They used two different bronze alloys for the shaft and the point, so when you stuck the shaft in a hole in the point, and then heated it up to a high temperature, the shaft fused to the point. There was more tin in the shaft, which probably made it fuse together. Tin will help all kinds of different metals melt together. The shaft was also a little bit more flexible metal than the point metal was.
When it hit, the solid pointed point with the attached metal shaft was probably more like a bullet than an arrowhead.