I recently got my hands on a Derya MK12, lovely little shotgun. The issue im having with her is cycling; she eats up challenger magnum slugs but theyre costly. Im wondering if anyone has the specs on Challengers tactical slugs as they are available in bulk and not breaking my bank. The challenger 00Buck runs smoothly aswell but i cant find specs. I know the magnum slugs are 1610fps. Any info is greatly appreciated, Thanks!