Description
To double pump you need to follow these steps:
1. Shoot
2. Reload
3. Switch to your second pump
4. Shoot
5. Repeat
You have to keep practicing to get the timing down. This can be very inconsistent and wont always work and it's difficult to aim while you're doing this if you're using a controller but it's still fun to use. You won't get banned for doing this but Epic will likely patch this in the next update.