Sling for Hammerli 850

Hello, I have a friend whos' son has a 850. He ask if I could install a sling for him. After looking at images of the gun online is see some issues with this.
1. Studs can't be installed on end of forearm, this is a removable cap. Would have to install stud after cap (middle of forearm).
2. Thickness of forearm too thin, studs may not hold and/or interfere with CO2 cartridge.

Has anyone tried intalling a sling on this gun? If so any advice would be appreciated.

Thx!