ProMag Armorer's Lower Receiver AR-15 Action Block

The ProMag Armorer's Lower Receiver AR-15 Action Block is a gunsmithing vise block designed to solve one of the most common frustrations in AR-15 building and maintenance: holding the lower receiver steady while you work. If you've ever tried to wrestle a lower into position while juggling a tool in your other hand, you know why gunsmiths call this a "third hand" solution. This heavy-duty polymer block clamps securely into your workbench vise, giving you a solid, stable platform to mount your mil-spec lower receiver while you install pins, springs, detents, or perform maintenance. It's the kind of simple tool that transforms a frustrating job into something you can actually complete efficiently.

Built from injection-molded polymer and manufactured in the USA, the block is engineered specifically for mil-spec AR-15 and M16 lower receivers. The design lets you insert your lower onto the exposed work surface, where it stays put while you focus on the actual gunsmithing. Whether you're a first-time builder working through your first AR assembly or a seasoned armorer performing routine maintenance, having both hands free to work makes a real difference in speed and accuracy.

This is a no-frills, no-nonsense accessory—it does one job and does it well. If you're building or maintaining AR-15s with any regularity, it's an inexpensive addition to your workbench that pays dividends in convenience and safety.

Key Features

• Vise-mounted design frees both hands for gunsmithing work
• Heavy-duty injection-molded polymer construction
• Fits mil-spec AR-15 and M16 lower receivers
• USA-made quality
• Solid, secure working platform for lower receiver assembly and maintenance

Frequently Asked Questions

What AR-15 lower receivers will this block fit?

The ProMag Armorer's Block is designed for mil-spec AR-15 and M16 lower receivers only. If your lower is mil-spec compliant, it will work with this vise block.

Do I need a vise to use this block?

Yes. The block is designed to clamp into a standard workbench vise. You'll need a vise with enough jaw capacity to secure the block firmly.

What gunsmithing tasks can I do with this?

The stable platform lets you install trigger groups, safety levers, pins, springs, and other lower receiver components, as well as perform routine maintenance and inspection. Any task where you need both hands free while the lower is held securely.