Perfect for building your custom Mk4 upper group. Comes with properly installed M4 barrel extension. All barrel sub-assemblies are properly head spaced. Made of 4140CM with a SBN Finish.
- 1:16 Twist 4140 Chrome moly
- 1/2X28 thread pitch
- Medium taper profile
- Carbine length gas port .750 gas block Journal"
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Some firearms, magazines, and accessories are restricted or prohibited in certain states, cities, and counties, and these laws change often. Each order is manually reviewed against the current laws for your shipping address before it ships. If we can't lawfully ship this item to your location, we'll contact you to cancel or adjust your order and issue a refund. You're responsible for knowing and following the laws where you live — if you're unsure, please check or ask us before ordering.
