The design takes stability and strength into account. It's very resistant to overturning. The base diameter is 63mm, which is very suitable for my HK Army ammunition bag. The funnel can be tightly placed in the base, making it easy to store in your bag.

I printed it using PLA material, but I think other materials would work just as well.
My printing settings:

0.4mm nozzle
Wall cycle: 3
Sparse filling density: 20%
Sparsely filled pattern: Gyroid

If you need a wider version that applies to other ammunition pack brands, I can make it. Please let me know!