Anthony, it is not truely Fully Supported but has more case support than previous Gen's. It has handled my handloads of Blue Dot and 135gr Noslers at 1700fps no issue. I shoot Underwood, Doubletap and Buffalo Bore frequently and have no issues.

Rudy the unsupported case is what causes the Glock bulge and makes the brass weaker for a reloader The feed ramp intrudes into the chamber and leaves part of the brass unsupported so the brass expands more there it does make a case failure more likely

I have no idea what that even means. It must not be important if Glock doesn’t say much about it.

From what I understand it is ore supported than the older Glocks I would suggest that you contact Glock and get the answer straight from them Phone: 770-432-1202
FAX: 770-433-8719