Mad Bull Airsoft has sent in some info regarding the WA M4 delta ring adapter:
One of Airsoft players share this information with us:
WA M4’s delta ring adapter is 0.3mm thicker than regular M4 (CA/ TM/ Real M4) adapter.
When you install a standard dimension handguard rail (like most of the brands), it won’t fit.
So, this guy used our Delta ring modification tools and modify his own WA M4.
Now, he can install regular handguard rail!!! This may be a solution for all WA M4 users.
We don’t have a WA M4 …so…try at your own risk. (Mad Bull Airsoft)