Hello Patrick,

Yes i use the GP11 Ammo it is like you said there is no way to get cheaper and better ammo than this. Thats good that there is more of this excellent ammo. My shooting at the LM ZG1 yesterday wasn`t the best had a problem with the scope but the fun was great. So i wish you good luck for the Black Powder shooting.
Hope to hear from You

Best Regards

Gunner