This increases the ammunition capacity of the hunting rifle by 5 rounds, from 5 to 10. Visually, it makes the magazine box extend beyond the bottom of the rifle's stock.
- Alexander, 188 Trading Post.
- Arms merchant, 188 Trading Post.
- Blake, Crimson Caravan Company.
- Dale Barton, The Fort.
- Vendortron, Gun Runners.
- Chet, Goodsprings General Store.
- Cliff Briscoe, Novac.