T.REX Criterion Barrel Kit
Video | What’s Included | Specs | Installation | Pictures | Restrictions
Criterion barrels have been our preferred barrels for quite a few years now because they offer an excellent balance of value and performance. These barrels are made from 4150 CrMoV and chrome-lined for extended barrel life and corrosion resistance. Over the years, chrome-lined barrels have gained the stigma of being less accurate than non-chrome-lined barrels, but Criterion’s highly refined chrome lining process, paired with their honing and hand-lapping processes, provide an exceptionally uniform bore and a pristine internal finish leading to great accuracy, consistency, and overall reliability.
The CORE profile itself has become a favorite of ours since its release a few years ago. The CORE uses a .625 gas block journal, typical to most pencil-style barrels, but features a constant taper profile that keeps weight towards the chamber where it is needed most. Doing this provides a light and accurate barrel that redistributes weight very well, keeping most of the weight towards the middle of the rifle and the front-end light for better handling, balance, and speed. This is especially useful on rifles with lasers, lights, suppressors, and other attachments toward the front of the gun. Paired with the hand chrome finish and sand cuts of the KAK bolt carrier you’ll have the heart of the rifle complete with something that will provides top-notch performance and long-term reliability in a package that punches far above its price tag.
Also in this kit are all the necessary solvents and greases to properly assemble your upper receiver, including Aeroshell 64 (33MS) Anti-Seize Grease for receiver threads, Loctite 620 Retaining Compound to bed the barrel in non thermal fit receivers, and Flexbar Rocksett for the gas block set screws and suppressor mounts, should you choose to add your own.
VIDEO
WHAT’S INCLUDED
- 1x T.REX Criterion Barrel Kit
- 1x Criterion Barrel
- 1x KAK K-SPEC Bolt Carrier
- 1x BCM Headspaced Bolt
- 1x BCM Cam Pin And Firing Pin Replacement Kit
- 1x 1/2×28 A2 Muzzle Device w/ Crush Washer
- 1x Badger Ordnance Gas Block
- 1x BCM Gas Tube
- 1x Loctite 620 Retaining Compound
- 1x Flexbar Rocksett
- 1x Aeroshell 64 (33MS)
SPECS
KAK BOLT CARRIER FEATURES
- Angled carrier rail cuts (Sand Cuts) for flawless function in adverse conditions and prolonged suppressed use.
- Standard side venting.
- Full auto profile.
- Permatex added between the gas key and carrier mating surface.
- Carrier – 8620 steel, outside rails, bolt runs, and gas bores ground to .0002 tolerances, hard chrome finish.
- Gas key – 4130 steel, heat treated, secured with T25 torx fasteners, torqued to spec, staked with hydraulic staking machine.
BARREL FEATURES
- Chrome-lined for superior barrel life and corrosion resistance. Criterion’s chrome-lining process is the most refined in the industry and will not degrade accuracy.
- .223 Wylde chamber that is designed to safely and reliably fire both .223 Remington and 5.56 NATO ammunition while increasing accuracy due to more consistent chamber pressures.
- Honed and hand-lapped rifling produces perfect bore uniformity and a pristine internal finish – aids in barrel cleaning and is paramount for accuracy.
- Finely polished chambers for reliable extraction and feeding.
- Gas port tuned for proper function with and without suppressor.
- 0.625” Gas Block journal, dimpled for ease of installation and solid lock-up.
- 1/2×28 TPI muzzle threads compatible with a wide range of muzzle devices and suppressors.
- Precision-machined barrel extension with M4 feed ramps.
GAS BLOCK FEATURES
- 416 stainless steel construction.
- .625 gas block journal.
- Black oxide finish.
- Stainless steel cupped set screws.
GAS TUBE FEATURES
- Stainless steel construction.
- Includes roll pin.
BCM BOLT FEATURES
- Headspace checked by Criterion to meet their specifications.
- Bolt assembly machined from Mil-Spec Carpenter No. 158 steel, shot peened.
- Tool steel extractor with BCM extractor spring.
- Tool steel ejector.
- HPT (High-Pressure Tested) and MPI (Magnetic Particle Inspected).
Made in the USA.
TECHNICAL SPECIFICATIONS
| BARREL TYPE | 16″ CORE |
| System Weight (Barrel+Gas System) | 31.5 oz (892g) |
| Twist Rate | 1:8 |
| Chamber | .223 Wylde |
| Gas System Length | Mid-Length |
| Gas Journal Size | .625 |
| Thread Size | 1/2×28 |
| Material | 4150 CrMoV |
| Finish | Phosphate/Chrome Lined |
INSTALLATION
BARREL INSTALL
- Wipe off excess oil from the packaging and thoroughly clean the oil out of the chamber.
- Apply a small, even amount of Loctite 620 to the barrel extension. If using a thermal fit upper, we recommend a light coat of Aeroshell 64 (33MS) instead of Loctite 620.
- Insert the barrel extension into your upper; if using a thermal fit upper like BCM or similar, heat threads with a torch (do not exceed 250°F).
- A heat gun can work here, but it will take significantly longer. You can also use an oven, as long as you wear gloves when handling the hot receiver. Be sure to have the receiver hot enough and move quickly; stuck barrels in thermal fit receivers aren’t fun to remove. See THIS VIDEO for our preferred install method for thermal fit receivers.
- Apply a generous amount of Aeroshell 64 (33MS) to the upper receiver threads, install the barrel nut, and torque it to the recommended specs.
- If using a new upper, season the threads by tightening the barrel nut to about half of your final torque value and then back the nut all the way off. Repeat 2-3 times.
GAS SYSTEM INSTALL
- Install the gas tube (hole facing downwards) into the gas block with the provided roll pin.
- Ensure correct installation by blowing air through the assembly; it should be free-flowing.
- Slide the gas block assembly onto the barrel and lightly snug the rearmost set screw so that the dimple in the barrel pulls it into alignment.
- On the front screw, clean the threads and apply a small amount of the included Rocksett.
- Torque front screw to 25 in/lbs. Then repeat the above process for the rear screw and torque to 25 in/lbs. Allow 24 hours for a full cure.
- Install handguard and muzzle device to manufacturer specifications.
PICTURES
RESTRICTIONS
This product cannot ship to Washington State due to unconstitutional restrictions. Because we believe that all citizens should have the same rights, we will not make any exceptions for military, law enforcement, or government personnel.
Products in this kit cannot be shipped outside of the US.
