The Grenade Launcher and Flare Gun can only be reloaded in Creative Mode. In Survival mode, they can be fired but not reloaded. Also, both of the weapons obtained in Creative mode will only fire the same rounds.
And sometimes, but not always, the game crashes when I choose a HWG item in the hotbar or check the tooltip in.

crash-2024-09-23_06.35.03-client.txt

I have installed all the required dependencies and they are also up to date. and My mod loader is neoforge 21.1.54.