Forward Controls Design Ar-15/M16 Gas Tube Pin Tool

The Forward Controls Design AR-15/M16 gas tube pin tool—or GPT—is a purpose-built jig that transforms one of the most tedious AR assembly tasks into a straightforward, one-handed operation. Installing or removing the gas tube roll pin on a low-profile gas block has traditionally required the kind of three-handed coordination that doesn't exist. This tool changes that. Machined from 6061 aluminum and hard-coat anodized, the GPT gives you a stable platform that keeps your gas block exactly where it needs to be while you tap the pin home or drive it out.

The design philosophy here is practical. Most low-profile gas blocks have no flats to grip, and sitting a black gas block in a black jig makes it harder to see what you're actually doing. FCD's answer was anodized green—not for looks (though it does look sharp), but because contrast on the workbench matters. The tool's base is intentionally thick and wide for stability, with a rebated edge that clamps securely in a vise, freeing both your hands. Scalloped finger recesses and rounded edges show attention to the details that make gunsmithing less frustrating. A built-in neodymium magnet holds the tiny roll pin upright and ready, so you can position it precisely and start driving it straight on first tap.

The GPT fits most modern Crane Mk12 pattern low-profile gas blocks—including those from Modern Armory, Forward Controls, BCM, Rainier, VLTOR, Knight's Armament, Badger Ordnance, Daniel Defense, and SLR. Confirm your gas block dimensions before ordering: the tool is designed for blocks up to 1.00" long and 1.35" tall. Known incompatibilities include Aero, Luth AR, and DPMS low-profile designs, plus adjustable gas blocks. If your block exceeds the maximum length, FCD can modify the tool to fit.

Key Features

• Holds low-profile gas blocks securely, eliminating the need for extra hands during pin installation or removal
• Thick, wide base with vise-compatible rebated edge for stable clamping
• Integrated neodymium magnet positions the roll pin upright for precise, repeatable tapping
• High-visibility green anodize finish provides contrast against black gas blocks for better workbench visibility
• Ergonomic scalloped recesses and rounded edges reduce hand fatigue during repetitive work
• Compact footprint designed to fit on crowded workbenches
• Compatible with most Crane Mk12 pattern low-profile gas blocks from major manufacturers

Specifications

Frequently Asked Questions

Will the GPT fit my low-profile gas block?

The GPT is designed for Crane Mk12 pattern low-profile gas blocks with a maximum length of 1.00" and maximum height of 1.35". It's compatible with Modern Armory, Forward Controls Design GBF, BCM, Rainier, VLTOR, Knight's Armament, Badger Ordnance, Daniel Defense, and SLR gas blocks. It does not work with Aero, Luth AR, DPMS, or adjustable gas blocks. If your block exceeds 1.00" in length, FCD can modify the tool—contact them directly. Verify your specific gas block dimensions before ordering.

What's the purpose of the magnet, and how does it work?

The integrated neodymium magnet is strong enough to hold the gas tube roll pin upright and perpendicular to the gas tube, positioned directly above the hole. This lets you start tapping the pin straight on without fumbling to align it, and without dropping it—a huge time-saver when you're working alone.

Can I clamp the GPT in a vise?

Yes. The tool's base is rebated specifically to allow secure vise clamping. This frees both hands so you can hold the gas block steady with one hand and drive the pin with the other.

Why is the GPT green instead of black?

Green anodize was chosen for practical contrast on the workbench. Since most gas blocks are black and most gunsmithing jigs are also black, sitting a dark gas block in a dark tool makes it difficult to see what you're doing. The green finish makes the black gas block stand out visually, improving visibility during precision work.