i dug up a toy pistol crossbow that shoots suction cup darts, but pretty sturdy plastic,
i put a 400mm / 7mm dia. fiberglass tent pole through it, [edit: 8.5mm tent pole]
invested in some 3mm dyneema, for bowstring,
running through the tent pole,
took a couple of strands out of it though,
and to draw it, i tied on 2.5mm v.b cord as a handle,
using ezelius knots,
they are holding pretty well.
took the cutter rail off a box of plastic wrap, to use as arrow track
the draw weight is 14lb according to my luggage spring scale,
which makes it an outdoor bow.
i'm shooting 7" arrows, 3 to 4 meters
the dyneema is working well 🏹
apart from an acute angle on one of the ends of the tent pole starting some wear in the dyneema -
which i have smoothed out -
happy to report that there is no other sign of wear on it