A.B.S. Ambi AR-15 Builder Set

Five of the parts that usually come from five different places, cut in one shop to work together. That is the whole argument for this kit: the receivers index to each other, the rail is built for that upper's barrel nut, and the gas block fits under the rail without anyone having to find that out the hard way.

In the set

• UHP-15A ambidextrous lower, five-axis machined from 7075-T6 billet
• UPUR-1 upper, precision five-axis machined from 7075-T6 billet
• UHPR HDX 13.7 in. M-LOK handguard with its barrel nut
• J.A.G. .750 in. low-profile gas block
• CFC 556 hybrid muzzle device

The lower

• Machined from 7075-T6 billet on five-axis CNC equipment
• Type III hardcoat anodize (MIL-A-8625 Type III, Class 2)
• Wire-EDM magazine well profile, flared for fast reloads
• Integrally machined trigger guard — nothing to snap off
• Mil-spec .154 in. trigger and hammer pin holes
• Reinforced buffer tube boss
• Lifetime warranty against manufacturing defects
• Ambidextrous bolt catch and magazine release, nitrided and aggressively textured
• Ambi magazine release runs on standard mil-spec internals — no proprietary parts to source

Check the gas length before you buy a barrel. A 13.7 in. rail wants a mid-length gas system on most barrels in that range. Confirm your barrel's journal is .750 in. so the included gas block fits.

What is not included. A receiver set is a foundation, not a rifle. You still need a barrel, a bolt carrier group, upper and lower parts kits, and a stock or brace assembly to finish the build.

This is a serialized firearm receiver. It ships to a licensed dealer for transfer, not to your door. You must be 21 or older. Give us your dealer's information at checkout, or we will ask for it before the order ships.