A quick advisory from RA-Tech regarding their M4 Forged Receivers for those who are using WE Airsoft Gas Magazine. Both the WE M4 Open Bolt Version Gas Magazine and the WE M4 20-round magazine will not fit the Forged Receiver. We don't know if there's a workaround or modding that will be required to make them fit, and if you know of one, drop us a note.