Ask the Community

Telly, a few but, most are not. Accessory websites have separate listings for the GSG 5 and the upgraded GSG 16. : https://www.thefirearmblog.com/blog/2019/07/15/tfb-review-american-tactical-gsg-16/

Telly, Generally no. You would have to go to some forums to find out specifically what accessories are interchangeable. Magazine comparability is about it.