Details
This is a brand new Sig Sauer MCX Conversion kit to convert your MCX Rattler from .300 Blackout to 5.56mm NATO with a 5.5" Barrel or can be used as a backup barrel assembly for your existing 5.56mm Rattler. This kit will ONLY work on an MCX Rattler. If you have an MCX that is not a Rattler model this will NOT WORK on your MCX.
All NFA rules apply.