u/karis891 · 2021-08-12 20:00:29 UTC · score 2
I believe the FCG9 is more of a derivative of the AP9, not the WTF9. AP9 also had a buffer tube and was the WTF9's predecessor.
The mod9 series solves your issue of Glock barrels in the WTF9, although the ECM barrel isn't as publicized. It's out there but it takes more digging to get ahold of. The documenta…