Daniel Defense Barrel Replacement Kit, 5.56 NATO, 10.3″, 1:7, Government Profile, Carbine-Length

Product Description

The Daniel Defense Barrel Replacement Kit, 5.56 NATO, 10.3″, Government profile, carbine-length is a 1:7 twist replacement barrel package in the MK18 close-quarters length, intended for firearms that are already registered as short-barrelled rifles or configured as pistols.

Short barrels wear hard. High port pressure, short dwell, a great deal of heat concentrated in a small mass of steel, and often a suppressor trapping more of it: a 10.3″ barrel that has seen serious use will show throat erosion sooner than a 16-inch barrel would. Replacing it restores the gun rather than replacing the upper, which is the point of a kit like this.

Ten point three inches with carbine-length gas is the shortest practical AR-15 arrangement and the pattern associated with the MK18. It gives up muzzle velocity against every longer barrel and it runs at high port pressure with minimal dwell, which makes the gun sensitive to buffer weight, spring rate and ammunition. What you buy is genuine compactness, which is exactly why people build these guns.

Key Facts

• Brand: Daniel Defense
• Model: Barrel Replacement Kit, 5.56 NATO, 10.3″, 1:7, Government, Carbine-Length
• Manufacturer Part Number: 28-101-07435-023
• Caliber: 5.56 NATO
• Barrel Length: 10.3″
• Twist Rate: 1:7
• Barrel Profile: Government
• Gas System: Carbine Length

This kit is for an SBR or a pistol, not a rifle

The kit itself is a component and not a firearm, so it requires no FFL transfer, no Form 4473 and no background check. The National Firearms Act applies at assembly. A 10.3″ barrel installed on a rifle-configured receiver creates a short-barrelled rifle requiring registration with BATFE, an approved transfer through an SOT dealer and a tax stamp. Unlike a 14.5″ barrel, no permanently attached muzzle device can bring 10.3 inches to the 16-inch rifle minimum. Western Sport is an SOT dealer, so the registration route can be handled here. If you are not certain how your firearm is classified, send us a message before you order.

Specifications we will confirm rather than guess

One honest note before you order. There is no published specification sheet for this Barrel Replacement Kit, so we state only what the kit’s own designation establishes: 5.56 NATO, 10.3″, 1:7 twist, Government profile, carbine-length gas system. We are not going to quote a weight, a muzzle thread pitch or a packing list by borrowing figures from a different barrel.

Compare the individual short barrels in our Daniel Defense barrels, browse our MK18 products for pattern parts, or see our suppressors if this gun runs a can.

Ordering from Western Sport

Order online and it ships straight to your door. Western Sport has been a licensed FFL/SOT dealer since 2007, and everything we sell carries the full manufacturer warranty. Questions before you order? Send us a message.

Frequently Asked Questions

Q: Can I put a 10.3″ barrel on my AR-15 rifle?

A: Not without NFA registration. A 10.3″ barrel on a rifle-configured receiver creates a short-barrelled rifle that must be registered with BATFE and transferred through an SOT dealer with a tax stamp. No permanently attached muzzle device brings 10.3 inches to the 16-inch rifle minimum.

Q: What is included in this replacement kit?

A: There is no published packing list for this kit, so we will not state one we cannot verify. The designation does establish 5.56 NATO, 10.3 inches, 1:7 twist, Government profile and a carbine-length gas system.

Q: Why do short barrels need replacing sooner?

A: Heat and pressure. A 10.3″ barrel with carbine gas runs at high port pressure with very short dwell, and the heat generated is concentrated in a small mass of steel. Suppressed use adds to it. Throat erosion and accuracy loss therefore appear at lower round counts than on a 16 or 18-inch barrel.

Q: Do I need a tax stamp to buy this kit?

A: No. A barrel is a component rather than a firearm, so the kit ships to you with no FFL transfer and no stamp. The stamp question relates to the firearm you install it on: a rifle-configured receiver becomes a short-barrelled rifle requiring registration, while a pistol-configured firearm does not.

Q: Will my existing gas tube and handguard fit?

A: If your gun is already a 10.3″ carbine-gas build, they should carry across, since this kit is the same length and gas system. If you are changing lengths, expect to change the handguard and possibly the gas tube. A carbine-gas barrel requires a carbine-length gas tube specifically.

Q: What thread pitch is the muzzle?

A: We will not quote a thread pitch for this kit, because there is no published figure for it and taking one from a different barrel is how buyers end up with a device that will not fit.

Additional information