Umarex T4E HDR68/TR68 Upgrade Guide: Complete CO₂ and HPA Video Series

A multi-part installation is easier to understand when each video has one job. Treating the three titles as unrelated clips would hide the prerequisites and could make the final HPA conversion look like a standalone first step. The transcripts and publishing order confirm that these videos form one continuous guide.

The complete series at a glance

Part 1: install the foundation

The first video begins with the internal upgrade work. It shows the power pin from the PowerKit being installed—not a full set of PowerKit components—and the housing being prepared for the opening required by the Z-Extension or ASA-to-chamber route. That preparation matters because both later configurations depend on a correct chamber connection.

Part 1 is not the finished marker configuration. It is the mechanical foundation for the parts shown in Parts 2 and 3. Confirm the exact marker version and the matching kit before disassembly, and follow the full video rather than treating this summary as a substitute for the installation sequence.

Part 2: finish and test the 12 g CO₂ build

Part 2 continues directly from the prepared marker. The video adds the tuning barrel, two Z-Extensions, the sniper extension, and the Z-DRUM. The Z-DRUM is not decorative: it creates room for the longer Z.68s projectiles that do not fit the stock HDR68/TR68 drum.

The video then performs the CO₂ chronograph test and presents the 47-joule result in the title for that filmed configuration. That number belongs to the exact parts, projectile, gas state, seals, temperature, and measurement conditions in the video. It is not a guaranteed result for every marker or every assembly.

Part 3: convert the gas path to HPA

Part 3 is the series’ HPA branch. The Z-Extension gas path used in the CO₂ build is replaced by an ASA-to-chamber adapter and an HPA bottle. The video separately recommends an On/Off adapter as an optional handling aid; it does not show that adapter as installed and does not make it a prerequisite for the HPA configuration. Without one, the video instructs the user to relieve the pressure safely before unscrewing the bottle. The filmed setup uses a 1,100 PSI regulator, loads Z.68s through the Z-DRUM, and reports a 91-joule test result.

The current Z-RAM HPA bundle is titled “100 Jo. HPA,” while the Part 3 video title reports 91 joules. Those numbers should not be blended into one promise. The page title identifies the current package; the video documents one earlier measured configuration. Actual energy can change with pressure, projectile mass and fit, valve timing, barrel, seals, temperature, and chronograph conditions.

Watch the complete series in order

Choose the matching configuration

Z-RAM Upgrade Package for HDR68 TR68 (47 Jo. 12g CO2)

Included: two Z-Extensions, tuning barrel with standard extension, sniper extension, Z-DRUM, vertical grip, and six Z.68s.

Additionally required: the original driver from the stock drum. A version-matched PowerKit is recommended separately by the product record but is not included.

Buying boundary: when choosing the package, do not add its included parts again as required individual purchases. The title’s value is setup-specific; verify the actual marker with a chronograph.

View CO₂ package

Z-RAM Upgrade Package for HDR68 TR68 (100 Jo. HPA)

Included: 1,100 PSI regulator and bottle, ASA-to-chamber adapter, tuning barrel with standard extension, two sniper extensions, Z-DRUM, vertical grip, flexible buttstock, and six Z.68s.

Not included: the marker, the stock-drum driver, a version-matched PowerKit, and the separately recommended optional On/Off adapter.

Buying boundary: do not rebuy included components. Use the correct pressure-rated route, and do not combine package-label and video-test numbers into a guarantee.

View HPA package

Z-RAM Z-DRUM Tuning Drum for Umarex T4E TR68 HDR68 (Z.68s fits!) BLACK

Why it belongs: Part 2 and Part 3 both use the drum to accommodate the longer Z.68s format.

Limit: drum fit does not establish compatibility with every .68 projectile.

View Z-DRUM

Which path should you choose?

Choose the 12 g CO₂ build when…

• You want to follow Parts 1 and 2 as one complete configuration.
• You want the Z-DRUM and longer Z.68s capability shown in the series.
• You prefer a compact capsule-based setup and accept that actual output and shot count vary.

Choose the HPA build when…

• You intend to replace the chamber-extension gas path with the ASA-to-chamber path shown in Part 3.
• You have the correct compatible bottle, regulator, ASA hardware, and filling arrangements.
• You will verify pressure compatibility, leaks, and measured performance for the completed system.

Before ordering, identify your marker generation and starting configuration, decide whether CO₂ or HPA is the final gas route, and compare the package contents with every part already on the marker. Treat the optional On/Off adapter as a separate convenience choice, not as proof that the HPA route cannot operate without it. If you only need to solve the ammunition question, see the HDR68/TR68 .68 ammo guide.

This three-part decision path remains specific to the Umarex T4E HDR68/TR68 .68 platform; neither its package contents nor its measured results transfer automatically to the .50 family or another marker.