Monobloc Barreled Rifles from HM Defense

    HM Defense & Technology manufactures AR-15 barrels that have an integrated gas block rather than a separate block that mounts onto the barrel. Now the company is shipping complete AR-15 rifles that use these barrels.

    According to the company, the Monobloc barrel offers advantages over the traditional gas block system. These benefits include:

    • no gas hole alignment issues – a potential failure point
    • no issues with different heat expansion rates that can affect gas hole alignment and gas block rupturing
    • no problems with increased back pressure from suppressed weapons


    The new Monobloc rifles are AR pattern guns designated HM15-MB-556. The guns use machined lowers and a 16″ Monobloc barrel. Additional specs on the guns include:

    • type III hardcoat anodizing
    • 12″ HM Defense hand guard with a Picatiny rail on top and M-LOK on the sides
    • quick change gas tube system
    • machined V1-556 flash hider
    • Magpul MOE pistol grip, adjustable length stock and 30-round magazine
    • HM Defense end plate with DQ attachment

    The guns do not ship with sights. However, the Picatinny rail allows for the addition of a wide range of iron and glass sighting options.

    The suggested retail price of the new rifle is $1,495. The rifles come with a five year warranty and a t-shirt with the company’s logo.

    Richard Johnson

    An advocate of gun proliferation zones, Richard is a long time shooter, former cop and internet entrepreneur. Among the many places he calls home is