Sam Yang/Seneca Big Bore M18x1 Adapter
- Made by CNC for accuracy
- Material is 6061 T6 Aluminum
- Matte black anodize
- Diamond pattern knurling for easy grip
- Compatible up to .357 to .457 cal
- Seneca .357 uses 5/8x18
Please note* Sam Yang has two different types of barrel threads, M16x1.5 and 5/8x18. Best way to determine which threads you have is to go to a hardware store and pickup one of the bolts. If the bolt does not screw on then it must be the other size. If your barrel is too close to the fill probe you will need to get the extended adapter version. I currently do not have the short version of the 5/8x18.