The Great Lakes AR15 M4 Barrel (brand part number 2231618BLK) is chambered in .223 Wylde, so it runs both .223 Remington and 5.56 NATO ammunition reliably out of the same 16-inch barrel. Machined from Mil-Spec CrMoV steel and finished in a durable black nitride, it’s cut with M4 feed ramps, a 1:8-inch twist, and a .750-inch gas block journal. Great Lakes threads the muzzle 1/2×28 so it’s ready for a muzzle device or suppressor mount, and ships the barrel as a bare, sight-free unit for a clean build.

Key Specifications

• Chambered in .223 Wylde, running both .223 Remington and 5.56 NATO.
• Measures 16 inches in barrel length.
• Rifled with a 1:8-inch twist.
• Machined from Mil-Spec CrMoV steel.
• Finished in black nitride.
• Cut with M4-style feed ramps.
• Sized for a .750-inch gas block.
• Threaded 1/2×28 for a muzzle device or suppressor mount.
• Ships with no factory sight cut.

Frequently Asked Questions

Can this run 5.56 NATO? Yes, the .223 Wylde chamber runs both .223 Remington and 5.56 NATO reliably.

What gas block size does this need? A .750-inch gas block.

Is the muzzle threaded? Yes, 1/2×28 for a muzzle device or suppressor mount.

Buy the Great Lakes AR15 M4 Barrel, .223 Wylde, 16 Inch, 1:8 Twist, Nitride

Build a reliable .223 Wylde upper around a Mil-Spec steel barrel. Order it from our Great Lakes lineup, part of our AR15 barrels selection, at our Lubbock, Texas gun shop for fast, direct shipping.