March 12 update:
I have since used this at a battle and it's made the Atlas much more fun to use! This might be my go-to springer from now on! Bear in mind that it won't feed properly if you overfill the hopper. The gravity-feeding takes some getting used to but once you get the hang of it the capacity is nice and the 2-shot gimmick is a blast.

Original description:
I revised the hopper on speardancer's Nerf Atlas hopper mod to utilize M3 brass inserts since they never specified what hardware their mod is using. I love brass inserts. I also added some lines in either side of the hopper to allow a user to view the ammo within. Use the original tube and rear adapter with these hopper parts to complete the mod.

I also reversed the screw direction for the cap but the original cap's dimensions didn't fit so I ended up not using it. Instead, the gaps I added are perfect to tie an elastic cord through, allowing a quick and easy way to load rounds without them falling out.

Note: I did not use any hardware to secure the tube. It fits securely between the hopper and blaster. Use M4 bolts/nuts to connect the hopper to the rear adapter.

Print side-down to minimize supports (the way the right side is orientated).

The tube and hopper don't fit snugly together. Not sure if it's an issue with my remake or present in the original design. It leaves a gap in the hopper but does not affect functionality. The adapter and hopper fit well together after a bit of sanding.

All in all an excellent design which will help make your Atlas more viable and interesting.

Creality

Ender 3

No

Yes

0.2

20