Guns Modify Magazine Gas Bucking #1/60°(+0.09or+0.14) TM G-Series ( 134A )

- Extreme Custom Mag Gas Buck #1/60°(+0.09or+0.14) 134A
- 0.05 thickness Stainless Steel shim x1
- For TM/GM G-Series

To find the best clearance by adjusting the positional relationship with the nozzle