Daniel Defense MK12 Gas Block, .750 (Commercial)

The Daniel Defense MK12 gas block brings a pedigree earned through USSOCOM contracts and Crane Division specifications straight to your AR-15 build. This .750-diameter low-profile gas block splits the difference between keeping your sight picture clear and delivering the durability you expect from a mil-spec component. Built from hardened 416 stainless steel with black oxide coating, it's precision CNC machined to tight tolerances and weighs just 1.9 oz—light enough to matter when you're counting every gram on a precision rifle, yet substantial enough to handle sustained fire without flex or play.

Daniel Defense manufactures the MK12 gas block in the USA, and it comes ready to install with everything needed: the low-profile block itself, two set screws, a gas tube roll pin, and a small bottle of Loctite 262 threadlocker. If you're running a Daniel Defense RIS II rail on an M4A1 or MK18, the gas block is designed to integrate seamlessly under that system. If you're mounting it to a naked barrel or under a rail that doesn't fully shroud it, compatibility is straightforward—.750-inch barrel diameter is all that matters.

This is the real deal: not a commercial approximation of a military component, but the actual gas block adopted for USSOCOM use, now available for civilian builders and gunsmiths. Whether you're building a precision rifle, running competitions, or just demand uncompromising quality in every part of your system, the MK12 delivers the kind of engineering and materials you can't fake.

Key Features

• Hardened 416 stainless steel with black oxide coating for corrosion resistance
• Precision CNC machined to Crane Division mil-spec standards
• Low-profile design minimizes optical obstruction
• Lightweight at 1.9 oz
• Made in USA
• Includes set screws, gas tube roll pin, and Loctite 262 threadlocker

Specifications

Frequently Asked Questions

Will this gas block fit my Daniel Defense rail system?

The MK12 gas block is specifically designed for the Daniel Defense RIS II rail family (M4A1 and MK18 models). If your Daniel Defense rail will completely shroud the gas block, you need to confirm RIS II compatibility before purchase. However, if you're mounting the gas block to a barrel without shrouding from the rail, it will fit any .750-inch barrel diameter regardless of rail system.

What's included in the box?

The package includes the low-profile gas block itself, two set screws, a gas tube roll pin, and 0.5 ml of Loctite 262 threadlocker—everything needed for installation.

What barrel diameter does this gas block require?

The MK12 gas block is designed for .750-inch barrel diameter. If your barrel matches that specification, it will fit (provided it's not being shrouded by an incompatible rail system).

Is this the military-spec component or a civilian version?

This is the actual commercial release of the gas block originally developed under the Naval Surface Warfare Center - Crane Division contract for USSOCOM. It meets the same specifications and is manufactured to the same standards as the military issue.