Cross Machine Tool UHPR Mod 2 HDX

Cross Machine Tool quietly manufactures handguards for some of the biggest names in the AR-15 industry, and the UHPR Mod 2 HDX is what happens when the OEM sells direct. The rail body is 6000-series extruded aluminum with Type III Class 2 hard anodizing, paired with a 7075 aluminum barrel nut and a patented 17-4PH cored stainless steel rail mounting attachment. That stainless lockup is the real differentiator: it resists deformation under repeated thermal cycles and impact loads better than the aluminum clamp systems found on most competitors.

The Mod 2 HDX runs M-LOK slots on all seven flat sides, giving full 360-degree accessory coverage without sacrificing rigidity. Anti-rotation tabs index the rail to the upper receiver, and the barrel nut requires no shims or timing. Two nitrided steel QD sling sockets sit at the 3 and 9 o'clock positions, included at no extra cost. The 1.315-inch inner diameter clears most low-profile gas blocks, and the rail floats over the gas tube without contact, so barrel harmonics stay clean.

Available in 6.7, 9.5, 13.7, and 15-inch lengths, the UHPR Mod 2 fills every standard barrel configuration. At roughly half the price of the premium rails it competes with on rigidity, the CMT is the open secret of builders who care more about metallurgy than brand logos.