This is our MAK90 flat with trunnion holes and the top rails machined.
Due to the dimensional differences between these and the other flats you will need to use a different punch for our die to bend these. Originally the receivers were made from .057" material and these are made from .050" annealed 4130. If you have already bought the bendind die from this website your user account should be activated to see the Chinese MAK90 punch for sale under the bending die category.
The internal dimension for the Chinese MAK90 receivers is 1.225" which is why a new punch will be needed. The other punches we have sold in the past are 1.208 or 1.250.
Currently we do not have the center supports that are narrow enough for these, but you can cut a 1mm center support down in length.
For such a small run of flats we didn't have new magwell dimple dies made so these use the RPK rails which will make up for not having the dimples.