SegaSonicSaiga

I am currently experiencing a problem with my S12. With the stock 5 rd mag and the 10 rd mad I can fire off 1 shot at a time but the gun will not eject the case. I am also having a greater difficulty with the 20 rd drum as it is not even feeding the rounds through properly. I recently purchased a 5 setting v-plug regulator, however I was experiencing this issue before it was installed. Has anyone else seen a similar problem? Thanks,