Nerf Slingstrike ammo loader

This is a replacement for the ammo loader/launcher for the Nerf Slingstrike. The product (and its accessories) has been discontinued, so when my son broke his, I decided to make this my very first project once I got my 3D printer. I'm still very much a novice when it comes to 3D modeling, so this is pretty basic, but it gets the job done quite nicely.

For reference, here is the broken piece in question:
https://i.imgur.com/EVqkOZ2.jpg