A mega dart
Scissors
Let's start.
First take your mega dart

Twist the head off of the foam

If there is a lot of excess foam on the head like there is on mine, rip it off.

Now you're going to want to draw a line around the two holes that make the dart whistle

Cut that line you just drew so your mold should be able to stand up and your done!

Fill the smaller hole with your hot glue and you can take your perfect dart head out by using a wedge or just making the rubber inside out.
Please use constructive criticism. This was my first writeup.