i've lost 3 darts thus far in my fetting. with my last set, i FINALLY found a good way to keep them in.
at the base of the spike, where you extended it, i carved a lcouple of small grooves all the way around with my dremel.
i drilled the hole in my gauntlets, and put some expoxy putty on the inside of the gaunt. i then pushed the darts in, got them all levelled out, then squished the putty around them, forcing it into the grooves. that way when it hardened there was a bit of extra grip to keep them from pulling out.
anyway, something to think about for those that are getting darts... it's worked well for me so far. i've had my present set of darts longer than anything i've had before.