SPIRO SR | DT 6mm/.243 | 5/8-24

The Thunder Beast SPIRO SR DT 6mm/.243 is available now from LM Ironwerks, a licensed FFL/SOT dealer in Louisville, Kentucky.

The SPIRO-SR is a version of the SPIRO that uses our SR (“Secondary Retention”) mount system, specifically SR v2. The SR system was designed from the ground up over a decade ago as a “fast attach” system with a “secondary retention” lock that retained the accuracy of precision rifles or sniper systems. The SR system itself is also full-auto rated and retains the original level of accuracy before and after full auto firing schedules.

WHAT IS THE SPIRO

The SPIRO is a low back pressure gas gun suppressor that has excellent sound suppression levels at both the muzzle and shooter’s ear. No longer do you have to compromise and have your gas gun suppressor be “low back pressure but loud at the muzzle.” It was designed around the 10.3 “MK18” 5.56 platform and has extreme durability since it’s made of Haynes 282, a nickel-chromium-cobalt-molybdenum “Super Alloy.” It is stronger than Inconel 718 and exceeds Inconel’s operating temperatures by about 500 degrees F. This makes the SPIRO almost indestructible. While our other “full auto rated” suppressors are guaranteed to last 10 cycles of the 8-mag SOCOM SURG test on a 10.5″ barrel, the SPIRO is rated for over 20 of the same cycles using an 8″ barrel instead of a 10.5″.

The SPIRO is available in Direct Thread, HUB, and SR (v2) versions.

The SPIRO-SR is only availble in 6mm/.243 bore size for flexibility. Our testing has found that on 5.56 hosts, the difference in overall performance (including sound reduction) of a .223 vs. .243 bore size is imperceptible to human senses, and the dB difference averages about +/- 1 dB(A) and depends on specific application and barrel length.

SR v2 – Secondary Retention mount, version 2

You might have read that and wondered, what is SR v2? SR v2 is a revision to the original SR mount. The only difference is that SR v2 is shorter than the original SR mount. This new revised length is roughly half an inch shorter to accommodate the future of low-back-pressure gas-gun suppressors and shorter, high-performing suppressors in general.

Suppressors designed for SR v1 (Dominus, Magnus, 338 Ultra) WILL WORK ON the SR v2 brakes.

The Spiro-SR will ONLY work on the SR v2 brakes. The Spiro-SR will NOT fit on the old SR v1 brakes, as they are too long.

The SR v2 brake is initially offered in a Non-Timed Brake (NTB) style. Additional mount styles for SR v2 may be available in the future. Each Spiro-SR will ship with one SR v2 brake.

People have been talking about “low back pressure” for a while, but there hasn’t been an objective method to actually quantify it. We weren’t satisfied with that, so we invented the TBAC Method of Measuring Back Pressure, and then we used the same sound-test setup we use at the SILENCER SUMMIT to make a very low-back-pressure suppressor that is also unbelievably quiet at both the muzzle and at the shooter’s ear, for a suppressor under 6″.

Specifications:

Mounts:

• Direct Thread 1/2-28 (DT)
• Direct Thread 5/8-24 (DT)

Buying the Thunder Beast SPIRO SR DT 6mm/.243 from LM Ironwerks

This is an NFA item, so it ships only to a licensed SOT dealer. Choose your dealer at checkout, and they’ll walk you through the transfer paperwork. In addition, our team reviews every order before it ships. Kentucky customers, please call us at (502) 430-1549 to order. For details on the process, see the ATF’s NFA page. Looking for something different? Browse all of our suppressors.