OSS HX-QD 556 suppressor

Product Description

The OSS HX-QD 556 suppressor is a centerfire rifle suppressor designed for .223 and 5.56 platforms using a quick-detach mounting system. It threads onto barrels with 1/2 x 28 threads for .223 or 5.56, or 5/8 x 24 threads for 7.62 or 300AAC. The QD mount allows you to attach and remove the suppressor without tools.

This suppressor reduces muzzle report and recoil for improved shooting comfort. It works on semi-automatic AR-15 pattern rifles and bolt guns chambered in compatible calibers.

As a serialized NFA item, the OSS HX-QD 556 requires ATF Form 4 approval before you take possession. An approved ATF Form 4 is required before you take possession; see our NFA wait times guide for current approval times.

Key Facts

• Brand: OSS
• Model: HX-QD 556
• Mount Type: Quick Detach (QD)
• Thread Compatibility: 1/2 x 28 for .223 or 5.56; 5/8 x 24 for 7.62 or 300AAC
• SKU: OSS-HX-QD-556

Quick Detach Mount: How the HX QD 556 Attaches

The quick-detach mount on the OSS HX-QD 556 lets you install and remove the suppressor in seconds. You twist it onto the muzzle device and lock it in place without needing an armorer’s wrench or extra tools. When you want to shoot unsuppressed, you unlock and remove it just as fast.

This makes the HX-QD 556 practical for shooters who switch between suppressed and unsuppressed fire during the same range session. The QD system also makes it easy to move one suppressor across multiple host rifles if they share the same thread pitch and compatible muzzle devices.

OSS Helix Technology and How It Differs

OSS suppressors, including models in the Helix line, use a flow-through design rather than traditional baffle stacks. Instead of trapping all the gas inside sealed chambers, flow-through cans redirect gas forward while reducing pressure at the shooter’s face. This approach reduces back pressure on semi-automatic gas systems.

Lower back pressure means less carbon buildup in the action, less gas blowback through the charging handle, and more reliable cycling with a wider range of ammunition. Shooters running adjustable gas blocks or suppressed short-barreled uppers often prefer flow-through designs for this reason.

Thread Pitch and Host Rifle Compatibility

The OSS HX-QD 556 fits barrels threaded 1/2 x 28, the standard pitch for .223 Remington and 5.56 NATO rifles. It also accepts 5/8 x 24 threads, which are common on 7.62 NATO and 300 AAC Blackout barrels. Confirm your barrel’s thread pitch before ordering if you are uncertain.

Suppressors rated for larger bores can be used on smaller calibers, so the 5/8 x 24 option allows use on both 7.62 and 5.56 hosts. However, always verify that the suppressor is rated for the caliber and barrel length you plan to shoot. Send us a message if you need help confirming compatibility with your specific rifle.

Ordering from Western Sport

Order online and we ship it to the licensed FFL dealer you choose near you — see how buying a gun online works. Western Sport has been a licensed FFL/SOT dealer since 2007, and everything we sell carries the full manufacturer warranty. Questions before you order? Send us a message.

Frequently Asked Questions

Q: What thread pitch does the OSS HX-QD 556 use?

A: The OSS HX-QD 556 suppressor is available with 1/2 x 28 threads for .223 or 5.56, or 5/8 x 24 threads for 7.62 or 300AAC. Confirm your barrel’s thread pitch before ordering to ensure proper fit.

Q: How does the quick-detach mount work on the HX QD 556?

A: The quick-detach mount allows you to install and remove the suppressor by hand without tools. You twist it onto a compatible muzzle device and lock it in place, then unlock and remove it when you want to shoot unsuppressed.

Q: Can I use the OSS HX-QD 556 on both 5.56 and 300 Blackout rifles?

A: The suppressor accepts both 1/2 x 28 threads (standard for 5.56) and 5/8 x 24 threads (standard for 300 Blackout and 7.62). Send us a message to confirm the suppressor is rated for your specific caliber and barrel length before ordering.

Q: What is the difference between OSS HX-QD and OSS Helix suppressors?

A: Both the HX-QD line and Helix models from OSS use flow-through designs that reduce back pressure compared to traditional baffle-stack suppressors. The HX-QD 556 specifically features a quick-detach mount for fast installation and removal.

Q: How long does the NFA approval process take for the OSS HX-QD 556?

A: An approved ATF Form 4 is required before you take possession; see our NFA wait times guide for current approval times. Western Sport handles the transfer paperwork as a licensed FFL/SOT dealer.

Additional information