Gemtech-Improved Outback Upgrade (IOU) Program

By Tom Murphy

Gemtech is a company, headquartered in Boise, Idaho, that has been building world-class suppressors since 1993. Gemtech, originally Gemini Technologies, was an outgrowth from Automatic Weapons Company, started by Dr. Phillip Dater in New Mexico in 1976. Dr. Dater had been working with suppressor design since the early 1960s. Later there was a move to Boise, Idaho, and in 1993, he started Gemtech with several other designers. Recently, American Outdoor Brands Corporation, parent company to firearms giant Smith and Wesson, purchased Gemtech. American Outdoor Brand’s CEO, James Debney, stated that the combination of Gemtech’s product development capabilities with American Outdoor Brands’ experience in brand management and manufacturing expertise will help to efficiently develop firearms and suppressors.

The Outback Suppressor

About 20 years ago, Gemtech introduced the Outback suppressor; a 3-ounce aluminum can with 1/2 x 28 threads to fit a .22 Long Rifle (LR) pistol or rifle. The original price was $299, which compared to other quality .22 LR suppressors, was a bargain price. Gemtech also offered adaptors to mate barrels threaded in 3/8 x 24 to the Outback.

This writer purchased an Outback 15 years ago and adapted a Savage MK II heavy barrel rifle by threading the muzzle to 1/2 x 28, which allowed the Outback to thread directly on the barrel without any adaptor. The MKII is a bolt-action rifle, and when subsonic ammunition like CCI’s .22 Long Rifle Hollow point 40-grain ammunition is fired, the sound is quieter than a .177 caliber air rifle.

The only concern that I’ve had about the Outback is that the female threads are cut directly into the aluminum. Some care must be used to ensure that the suppressor is not cross-threaded when installed on the barrel. Lately, the Outback is being shared between the Savage MK II and a recently acquired Ruger.22 /45 Lite NRA Commemorative MK III pistol. I always clean the barrel and suppressor threads with a product like Hoppe’s #9 and give both a good inspection with the Mark I eyeball. Having owned cars whose engine heads were straight aluminum with no steel spark plug inserts, I long ago learned that slow and easy was the only way to mate steel with aluminum. If the suppressor does not thread on the barrel easily, something is wrong. Remove the suppressor and recheck everything.

It’s possible to strip the threads by overtightening the suppressor, so don’t use a lot of force to tighten the suppressor when it rides up against the muzzle. A .22 LR-round doesn’t put out enough combustion gas to drive the suppressor against its threads with much impact.

Improved Outback Upgrade (IOU)

Gemtech has come up with an upgrade for the Outback, Outback- II, Outback-2D and the Outback-IIT that eliminates the possibility of thread stripping and adds to the functionality of these suppressors. The upgrade package includes:

This makes for easier maintenance when compared to my original Outback, which could not be disassembled. Plus, the upgrade is now rated for .22 Mag in addition to .22 LR, which opens up a whole new world of possibilities. Also, the suppressor will have a longer life and can be used for as long as the can itself is not destroyed. My favorite part of the upgrade is the ease of cleaning. Just unscrew the front cap, and the baffle stack will lift right out.

The Process

To send your Outback to Gemtech, you will need to include a copy of your Form 4 and fill out the General Service Form located on Gemtech’s website (www.gemtech.com/improved-outback-upgrade-iou-program) and purchase the $249 upgrade from them. Once they receive your suppressor, they will notify you through an email. Gemtech will give you upgrade notifications as the work progresses. An average upgrade will take between six to eight weeks.

Factory Work

The work involves a series of steps. First, the baffles must be removed. This requires turning off both ends of the suppressor tube, then driving the six baffles out with a drift. Then the tube is checked for runout and straightness, and both ends are threaded. A female ½ x 28 is then turned onto the muzzle end, and the monocore baffle stack is threaded onto the other end using a 15 /16 x 28-inch thread. Internal tube diameter is .90 inch. The exit port on the endcap of the monocore baffle stack is fabricated to accept a ¼-inch drive ratchet wrench that makes takedown and re-installation quite easy.
The IOU upgrade will make all Outback suppressors function with .22 Mag (Gemtech only!). It’s fully rated for full-auto fire but only with .22 Long Rifle. Note: The length of the Outback suppressor is too short to provide enough hearing protection for rounds like the 5.7 x 28. These and similar rounds should never be fired through an Outback. The end result of the IOU upgrade is easier maintenance, longer life and a better appearance.


The IOU-modified Outback was installed on my Ruger .22 /45 Lite NRA Commemorative MK III pistol. For testing purposes, only Gemtech Silencer Subsonic .22 Long Rifle ammunition was fired. Gemtech optimized this load for suppressor-fitted rifles and pistols. This ammunition launches a 42-grain bullet at 1,020 feet per second. On hand were some Aguila subsonic with 60-grain bullets and CCI 40-grain subsonic, but taking Dr. Dater’s advice, these were not fired. (After all, if you can’t follow your doctor’s advice, whose can you follow?)

All shooting was done at the Green Valley Range in Henderson, NV. Temperature on the firing line was 72 degrees during the entire shoot. The Ruger .22 /45 ran flawlessly while digesting a little under 200 rounds of Gemtech subsonic .22 LR. No sound readings were taken, but the range officer said that from outside the glass-enclosed shooting area, little or no sound was heard. When standard-velocity .22 LR ammunition was fired through the suppressor, the supersonic crack could clearly be heard. Shooting with the suppressor removed resulted in the typical .22 Long Rifle discharge.

Next up we fitted the Outback to a Savage MKII bolt-action rifle. The standard .22 Long Rifle had a definite reduction in sound; much more quiet than the pistol. When fed subsonic ammo, the report (slight pop) could not be heard by fellow shooters standing at the end of the range bay. It made less noise than prying a cap off a bottle of warm Coke. Without hearing protectors, all I heard was the bullet striking the backstop.

This suppressor can be shot wet, which will reduce first round pop and really quiet the output sound. Use only .22 Long Rifle ammunition with water or water soluble gel as a liquid. Gemtech recommends fully cleaning and drying the suppressor before storing.

The Outback suppressor was then removed and opened for cleaning. What residue that had adhered to the baffle stack was soft and easily cleaned. We used a sonic cleaner, but a good gun solvent and some brush work would have accomplished the same thing. Rather than cranking down on the suppressor when installing it on the barrel, we wrapped the barrel threads with Teflon pipe tape and only went hand tight. No problems with loosening so far.

This article first appeared in Small Arms Review V22N3 (March 2018)
and was posted online on February 9, 2018


Comments have not been generated for this article.