Maple Custom Products now has .30 cal magazines for the BRK Ghost. These are 7-shot, rotary style with magnets so you can load 2 mags for 14 shots!!
I have no affiliation with Maple but i requested these magazines for the .30, sent over a few specs based on the factory mag, and they developed them in about 3 days! These are SIGNIFICANTLY less expensive than the $125 factory magazines. No, they are not aluminum and hold 1 shot less but for the cost savings, they can't be beat. I've already fired about 21 rounds through each magazine and they have worked flawlessly.
maplecustomproducts.com 
I have no affiliation with Maple but i requested these magazines for the .30, sent over a few specs based on the factory mag, and they developed them in about 3 days! These are SIGNIFICANTLY less expensive than the $125 factory magazines. No, they are not aluminum and hold 1 shot less but for the cost savings, they can't be beat. I've already fired about 21 rounds through each magazine and they have worked flawlessly.
Brocock BRK Ghost / Daystate Alpha Wolf Delta Wolf self-indexing magaz
MAPLE Custom Products magazine Multi-shot magazine for Brocock / BRK Ghost and Daystate Alpha Wolf, Delta Wolf air rifles. Lightweight and super tough. Easy loading & smooth action. 2 magazines will stick back to back for added shot capacity. They will also stick with your factory mag
maplecustomproducts.com 