Gbb/HPA Groza OC 14

I hereby pre-purchase my Groza, original we aks74u converted with 3d print externals.
 Lots of recoil.
 Met Airtac UK hpa adapter voor WE aks74u.
 -1 working gbb allowed
 -3d print external mag
 -1 gbb mag of which the internals plug into the hpa adapter

 Original internals and externals are also included.

 Gun shoots perfect on gbb but has problems with hpa adapter.
 After a few shots, the firing pin slides above the release valve. Filing the firing pin should fix this.
 Pick up only, in Mechelen Belgium.