I LOVE Sergio's Crossbow mod found here: https://www.curseforge.com/hytale/mods/more-crossbow-tiers
It hasn't been touched in over a month, and I was wanting to expand the features of the high-tier crossbows.
It was quite the learning process but here are the changes:
Cobalt and Thorium have largely unchanged.
Iron Arrows are now craftable, 5 sticks + 1 iron ingot = 10 Iron Arrows
Adamantite and Mithril bow now REQUIRE Iron Arrows. They will only load and fire Iron Arrows.
Adamantite Crossbow now holds 8 ammo.
Mithril Crossbow holds 10 ammo.
Buffed Adamanatite and Mithril damage amounts to reflect the better arrow requirment..
Did all this without any JAR code at all.
Learned quite a lot about how the games back-end component system works...
ALL Credit for the models and awesomness of the Crossbows goes to Sergio. I overhauled and tested the bulk of the higher tiers.
If he gets mad at my work then I will be sad. I have no modeling skills and love his work.
I have received permission to upload this by Sergio:

Unless of course I have to upload the entire thread of our conversation. "no problem." is the response to my asking for permission.