CU-MNDRL-G3

The Copper Welding Mandrel minimizes excessive heat build up generated during welding process. Preventing warpage, shrinkage and burn-through holes in your HK Receiver. 

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NEW RELEASES

Tools & Jigs

RECEIVER FLAT BENDING
FORMING RECEIVER RAILS
ALIGNMENT & WELDING
THIS WEEK

New products

TOOLS & JIGS FOR WEAPON BUILDERS

Our story

Welcome to Weapon Builder, where we help elevate the art, beauty, and craftsmanship of the HK MP5 and G3 Platforms to an unparalleled level.

We are dedicated to serving the HK Weapon Builder Community and committed to providing the highest quality tools, jigs, and training for enthusiasts like you.

Our mission is to simplify your process of creating an exceptional HK Weapon System while achieving Factory-Level Precision and Results.

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THE WEAPON FORGE

Building HK 90 Series Rifles & Pistols

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Bending

How to Bend your Receiver Flat

Learn how to properly bend your HK Receiver Flat. We highlight the New RCVR-BNDR's ability to achieve perfect symmetry and seam alignment every time.

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Forming & Alignment

Form & Align your Receiver Rails

The inner dimensions, shape and spacing of your Receiver Rails is critical to function and reliability. Learn how to properly shape and space your Receiver Rails to ensure your Bolt Carrier Group (BCG) reliably cycles with every round. 

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Welding

Welding the Rear Sight Base

Learn how our New RSBA Jig helps you simplify the process of aligning and properly welding your Rear Sight Base. Creating a more accurate shooting weapon system.

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HK Tools & Jigs

Weapon Builder

Achieve HK German Factory-Level Precision with your next HK 90 Series build.  

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