Yankee Hill Machine Co Shim Set, Part, 1/2"" Inisde Diameter, Fits .556 Caliber SHIM-3102-SET

Getting a timed muzzle device to sit at exactly the right rotational angle is one of those details that separates a half-done build from one that actually works. The Yankee Hill Machine Co .556 Caliber Shim Set is engineered precisely for this job: it lets you dial in perfect timing on YHM's quick-detach muzzle brakes and similar .556 devices. With an inner diameter of 1/2", this set gives you the fine adjustability you need to ensure your muzzle device orients correctly without staking it permanently in the wrong spot.

Built from stainless steel, these shims resist corrosion and wear, so they'll stay accurate through multiple installations and removals. Whether you're running a suppressor-ready brake, a flash hider, or a compensator on an AR platform, proper shim selection is the difference between a device that functions as intended and one that doesn't. This isn't a flashy upgrade—it's a fundamental tool that makes your muzzle device work the way the manufacturer designed it to.

The set includes six individual shims in graduated thicknesses, giving you enough precision to fine-tune timing on a single build or have backups on hand. If you're building an AR with QD muzzle brakes from YHM or any other .556 platform that accepts 1/2" ID shims, these are essential to keep in your parts drawer.

Key Features

• Designed for .556 caliber QD muzzle brakes and similar devices
• 1/2" inside diameter fits standard AR muzzle device applications
• Stainless steel construction resists corrosion and wear
• Six shims in graduated thicknesses for precise timing adjustment
• Allows correct rotational orientation without permanent staking

Specifications

Frequently Asked Questions

What muzzle devices do these shims work with?

These shims are designed for Yankee Hill Machine Co 5.56mm QD (quick-detach) muzzle brakes and other .556 devices with a 1/2" inside diameter. They are compatible with standard AR platform muzzle threading and QD systems that accept 1/2" ID shims.

Why do I need shims for my muzzle device?

Shims allow you to adjust the rotational angle of your muzzle device so it times correctly—meaning it orients in the exact position the manufacturer intended. Without proper shims, your brake, compensator, or flash hider may not function as designed or may sit at an undesired angle.

What thicknesses are included in this set?

This set includes six shims: two shims of 0.002" thickness, three shims of 0.005" thickness, and one shim of 0.020" thickness. The variety allows you to stack and combine them to achieve the precise timing adjustment your build requires.

Can I use these shims on other manufacturer's muzzle devices?

These shims are sized for 1/2" inside diameter devices. As long as your muzzle device accepts 1/2" ID shims, they should be compatible. Check your device's specifications to confirm the bore diameter before purchase.