TM M870 feeding issues

[waz00da]

HI GUys,

having a bit of an issue with my m870.

the bbs load form the shell into the gun, but wont load into the chambers, gas runs fine through the gun, and blank fires fine.

What issues can cause feeding problems?

Cheers in advance

 

[Wavey_Gravey]

New or used and are you using TM shells?