The 338 ULTRA SR Gen1 was discontinued January 2022 and replaced with the 338 ULTRA SR Gen2
Click here to proceed to the new specs page.

High-Performance Suppressor with Secondary Retention (SR)
.338 Lapua Magnum caliber

The 338 ULTRA SR is our latest high-performance .338 caliber suppressor. It offers class leading suppression levels, a light weight design, and our "SR" quick attach/detach mount that offers locking Secondary Retention.

The 338 ULTRA SR will suppress a typical .338 Lapua Magnum bolt-action rifle down to approximately 135-138 dB at the muzzle1, and approximately 124-128 dB at the shooter's ear 2. It also has very little or no "first round pop" (FRP) in most applications.

The 338 ULTRA SR weighs 20.2 ounces including the SR mount mechanism on the suppressor itself. The SR brake weighs 3.6 ounces. It is only compatible with the 338 ULTRA SR series of brakes.


The 338 ULTRA SR represents the next step in the evolution of the 338 ULTRA suppressor, and more broadly, the next step for TBAC suppressor mounts. However, the 338 ULTRA SR will NOT replace the regular 338 ULTRA.

The 338 ULTRA SR has the same durability, longevity, and performance as the BA-mount 338 ULTRA but includes our new SR ("Secondary Retention") mount. This mount meets the mil spec represented in the 2017 Advanced Sniper Rifle (ASR) solicitication, and the 338 ULTRA SR is the suppressor that Accuracy International North America chose for their ASR rifle system submission.

The main feature of the SR mount is that it acts as a secondary, fail-safe, locking mechanism to retain the suppressor on the muzzle brake in all circumstances, unless explicitly removed on purpose, by hand. It also reduces the number of turns required to mount the suppressor due to a coarser thread and enables "Quick Mount" and "Quick Detach" functionality of the mount. The mount is mechanically very simply and user-level maintenance is possible.


The SR mount uses a novel paw and cam-path system to ensure that "full lock up" can happen in either of the two adjacent detent slots for any given final shouldering position of the suppressor on the conical brake shoulder. This categorically avoids the "off by one" problem that many "clicky" mounts have. The SR mount has the exact same accuracy, repeatability, and return-to-zero characteristics that all our precision suppressors are known for.

This mounting system is covered by US Patent 9,791,234.


The ULTRA series is constructed of titanium with a fully-welded core. This material and construction provide a great strength to weight ratio. It can take whatever your precision rifle can dish out.

The 338 ULTRA SR was designed around .338 Lapua Magnum for maximum flexibility and is rated with that cartridge down to 16" barrels. The 338 ULTRA SR can easily do multiple-rifle duty on 6mm's, 6.5's, .260's, .308, and most .30 caliber magnums.

Special Features

Ionbond DLC coating on 338SR brakes
Conical shoulder surface on mount
100% titanium construction of suppressor body
360-degree fully-welded baffle core
Magnum rated
Rock-Solid POI Repeatability
Patented SR brake with full lockup in at least two positions
Full 2017 ASR solicitation submission spec

Application Notes

Minimum barrel lengths:
   .300 Blackout: 8"
   6.8 SPC, 7.62x39: 10" *
   .223 Rem, 5.56, 6.5 Grendel: 11.5" *
   .308 Win: 14.5" *
   7mm RM, 7mm WSM, .300 WSM, .300 WIN MAG: 18"
   7mm RUM, .300 RUM: 20"
   .338 Lapua Magnum: 16"
Please contact tech support for:
   7mm cal loads exceeding 90 powder grains,
   .30 cal loads exceeding 100 powder grains
For questions about a particular rifle/load combination please contact us.

Please note that thermal input will be higher with shorter barrels. Ultra series suppressors should be kept under 800 degrees F.

1. "At the muzzle" (M) sound measurements are measured in accordance with MIL-STD-1474D using a B&K PULSE SLM one meter offset from muzzle of the suppressor
2. "At Shooter's Ear" (SE) measurements are measured in accordance with MIL-STD-1474D using a B&K PULSE SLM at the position of the shooter's right ear in a normal shooting position. SE measurements are affected by overall rifle length; we used an AI AXMC for our measurements.


Caliber .338 caliber, up to .338 Lapua Magnum or .338 RUM
Material Titanium
Length 11.0 inches.
Diameter 1.775 inches (suppressor body); 1.855 inches (rear collar)
Weight 20.2 ounces
Mount 338 ULTRA SR brake
Brake Threads 9/16-24, 5/8-24, 3/4-20, 3/4-24, 3/4-28, M15x1.0, M18x1.0, M18x1.5
Finish High-Temp CeraKote: Black, OD Green, FDE, Federal "20150" (ie, SURG Brown)
Use Precision/Long-range on big-bore magnums that require military-spec retention
Price $2195 (one brake included).
Extra brakes $145/ea
  (not included - sold separately)
Warranty TBAC Limited Lifetime Warranty
How to order a suppressor


SR Brake
Each brake includes one peel washer

Extra Peel Washers
Peel washers have an O.D. of 0.840-0.845"
and an initial thickness of approx 0.048-0.055".

NOTE: The collar is not intended to stay perfectly parallel/square to the body when locked. The play is there on purpose for clearance so foreign material does not compromise functionality of the locking mechanism.

Shipping for web orders is $8.65 for the first item and $4.33 for each subsequent item, for most products. Shipping cost on external thread protectors and extra peel washers is less. Bipods are more.