As many WA GBB M4 users have shortly discovered after purchasing, the Delta ring on the Upper receiver of their expensive little toys is not compatible with many after market modification parts (front-ends).  This is because the Delta ring threading is approximately .3mm thicker on the WA M4.

One un-satisfied WA M4 owner tried the Mad Bull D-Ring Mod Tool on his upper receiver, and it apparently worked like a charm.

Here’s the note from Simon at Mad Bull:

Gents,

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.

It should be noted that because Mad Bull hasn’t actually tried this themselves – you may want to take this with a large dose of salt.

For product info on the Mad Bull D-Ring tool, click the link below:

http://www.madbullairsoft.com/English/index.php?main_page=index&cPath=5