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Young Mfg Chrome AR-15 Bolt Carrier Group (BCG) - Full Auto (HMB Bolt)

Out of stock

Young Mfg Chrome AR-15 Bolt Carrier Group (BCG) - Full Auto (HMB Bolt)

$165.00

This is YM's standard M16 Bolt Carrier Group. As with all of their carriers they leave material on all critical areas then send them out for heat treat. Next they precision grind the carrier inside and out to remove any distortion caused by the heat treat process. All of the standard carriers have 30% wider rails than the typical Mil Spec carrier to give you more contact area in the upper receiver.

The HMB Bolt by HM Defense eliminates the pass through cam pin hole and replaces it with a cam pin socket and radiused cam pin design.  The new patented design eliminates the natural weak point of Mil-Spec bolts by significantly increasing the amount of metal (and strength) at the cam pin location.  The result- NO MORE BROKEN BOLTS!

The HMB Bolt also reduces contact between cam pin and firing pin, enabling smoother operation of firing pin, bolt lugs and aft gas rings.  The new cam pin socket also retains lubrication for extended operations.

Weight: 11.3 ounces.


"There has been a lot of talk about the pros and cons of staking the gas key on the carrier. Here is our opinion and why Young Manufacturing will not stake keys. We have been making carriers since 1991. The US Mil Spec. assembly drawing requires the carrier key to be staked. Contrary to some popular opinions staking does not SEAL the gas key. Staking keeps the screws from backing out Period. If you do not properly torque the screws to 56 inch pounds you will be staking a screw that is loose or one that is over torqued and prone to breakage. We have seen plenty of staked screws that are loose or broken. The Mil Spec. also calls for the gas key bottom surface to be SEALED with Permatex gasket sealer. Something no one does to our knowledge. Here is our procedure for installing a gas key. First clean the oil from the gas key and the mating surface on the carrier. Then clean the oil from the screw threads. We use brake cleaner for this. Next use a very light coating of Permatex high strength thread locker gel on the bottom of the key. PN 27010. This is much easier to use than the Permatex gasket sealer. It comes in a plastic twist dispenser. Make sure you dont use so much that it squishes into the gas port hole. The cure rate is 60 minutes. Next coat the screw threads with the same gel. Install the key and torque the screws to 56 inch pounds. Should you decide to remove the key for some reason dont use the old screws when you put the key back on! You will most likely break them during installation or when you fire the rifle. Go to the local hardware store and buy new 10-32 x ¼ SHCS. If you feel the need to stake the screws spend the money and get one of the staking tools from Brownell that uses a screw type system to swedge the material into the top of the screw. Dont use a hammer and a punch! You can stretch the thread on the screw and now you have a loose screw that will eventually break if the gun even fires. We will not warrantee a carrier with a staked key no matter who staked it. You will be charged for a new key and any labor required to remove broken screws.

Good Shooting!"

Daniel H Young
President

More Information
SKU YM55B-HMB
Manufacturer Young MFG