For feature requests, just erase this template and clearly describe the feature you'd like to see

Minecraft Version

1.16.1

Forge Version

32.0.108

Mod Version

pneumaticcraft-repressurized-1.16.1-2.2.1-32

Describe your problem, including steps to reproduce it

1. Build multiple jack hammers.
2. Hold the stack and enter the GUI
3. Insert an enchanted book and a drill bit.

All of the jackhammers get the book/drill, so if you separate the stack and access the GUI on each, you can pull out a book/drill bit from each.

Any other comments?

Probably best to make it non stackable to avoid this.

Oops, yeah.

Fixed in 2.2.2 release