This mod increases the ammunition capacity of the 10mm SMG by ten rounds, from 30 to 40.
- Alexander, 188 Trading Post
- Arms merchant, 188 Trading Post
- Blake, Crimson Caravan Company
- Dale Barton, The Fort
- Vendortron, Gun Runners kiosk
Prior to patch 22.214.171.1242, the 10mm SMG mags were only worth 250 caps.