How to get 9 mm Barrel Extension

Traded at 10

Settlement	Level	Cost	In exchange for
Mercenary Camp	2	76,900	1× Custom Guns Doncaster 57× Red Fern 148× Substance 07270 121× Remains of a Psy-Tracker 48× Gamma Data Fragment
Rise Base	2	76,900	1× Custom Guns Doncaster 57× Red Fern 148× Substance 07270 121× Remains of a Psy-Tracker 48× Gamma Data Fragment
Frontier Base	2	76,900	1× Custom Guns Doncaster 57× Red Fern 148× Substance 07270 121× Remains of a Psy-Tracker 48× Gamma Data Fragment
Covenant Abode	2	76,900	1× Custom Guns Doncaster 57× Red Fern 148× Substance 07270 121× Remains of a Psy-Tracker 48× Gamma Data Fragment
Factions of the North	2	76,900	1× Custom Guns Doncaster 57× Red Fern 148× Substance 07270 121× Remains of a Psy-Tracker 48× Gamma Data Fragment
Mercenary Camp	2	110,000	1× Custom Guns Doncaster 110× Bitterleaf 97× Limbo 21× Lambda Data Fragment 5× Limboplasma
Rise Base	2	110,000	1× Custom Guns Doncaster 110× Bitterleaf 97× Limbo 21× Lambda Data Fragment 5× Limboplasma
Frontier Base	2	110,000	1× Custom Guns Doncaster 110× Bitterleaf 97× Limbo 21× Lambda Data Fragment 5× Limboplasma
Covenant Abode	2	110,000	1× Custom Guns Doncaster 110× Bitterleaf 97× Limbo 21× Lambda Data Fragment 5× Limboplasma
Factions of the North	2	110,000	1× Custom Guns Doncaster 110× Bitterleaf 97× Limbo 21× Lambda Data Fragment 5× Limboplasma