Z-RAM describes roughly 20–30 Joules for its Umarex HDP50/TP50 PowerKit-and-bolt Starterkits and 25–35 Joules for the larger packages with Z-Extension, with “+” wording on several offers. Those are seller-advertised outputs for the respective combinations, not amounts to add to the original marker rating. The two package sizes are available as separate offers for the listed 7.5-Joule Gen1/Gen2 models and the 13-Joule Gen2 version.
Both package sizes already include a steel firing bolt. The larger package adds the chamber extension and its seal. This makes the central comparison quite specific: the difference is not “a pin versus a bolt,” but the same categories of valve-and-pin kit and replacement bolt, with or without a supplied extension.
Four offers, two package sizes
| Original version | Package | Advertised output | Extension included? |
|---|---|---|---|
| 7.5 J, Gen1/Gen2 | PowerKit.50 V2 + steel bolt | 20–30 J, depending on setup and temperature | No |
| 7.5 J, Gen1/Gen2 | PowerKit.50 V2 + steel bolt + Z-Extension | 25–35 J; description also says 35+ | Yes, with O-ring |
| 13 J, Gen2 | PowerKit.50 + steel bolt | 20–30 J+; description also mentions 30+ with temperature qualification | No |
| 13 J, Gen2 | PowerKit.50 + steel bolt + Z-Extension | 25–35 J+ | Yes, with O-ring |
The original-version labels identify which marker the offer addresses. They do not identify selectable output settings. Likewise, the V2 name on the 7.5-Joule PowerKit describes the component revision, not a restriction to Gen2 markers: those package descriptions explicitly name Gen1 and Gen2.
HDP50 and TP50 refer to the same .50 pistol platform under regional names. It is distinct from the HDR50/TR50 revolver. A bolt listed for both families does not establish that the complete PowerKit packages are interchangeable. The four product targets below are the HDP50/TP50 offers, including the explicit 13-Joule Gen2 package boundary.
What changes when Z-Extension is included
The extended Starterkits add a CNC steel Z-Extension and its O-ring. Its described function is additional chamber volume; the PowerKit has the separate valve-and-pin function. The second video helps distinguish those product categories by naming the PowerKit’s core components before discussing an extension separately.
The larger package couples the valve-and-pin function with more chamber volume, which is the performance-related difference described by Z-RAM. Its advertised 25–35-Joule range overlaps the smaller package’s 20–30-Joule range; these are not controlled measurements of an isolated extension gain. CO₂ temperature and the complete marker affect the result.
Why every package includes the steel bolt
The PowerKit supplies an insert and a stainless-steel Power-Pin. Z-RAM describes the separate black steel firing bolt as prepared for the included pin, with durable steel construction as a material benefit. The package description explains that working with the original pressed-in pin can damage that original part; supplying a replacement bolt is the practical answer offered by this combination.
That benefit exists in the package without Z-Extension as well as the larger one. It is therefore misleading to treat the bolt as an extra purchase needed to complete the smaller Starterkit. The separate firing-bolt explanation distinguishes a bare replacement bolt from a package containing the Power-Pin too.
The bolt video below uses the HDR50 in its spoken presentation. It is relevant here because the current HDP50/TP50 descriptions list that shared bolt, while the correct pistol-specific PowerKit remains determined by the package page. The video is component context, not a four-way HDP50 performance test.
Included hardware and avoiding duplicate purchases
Both 7.5-Joule delivery lists include the valve insert, stainless-steel pin, black steel bolt, Allen key and mounting screw. The larger 7.5-Joule package adds Z-Extension and its O-ring. The 13-Joule package without extension lists the insert, pin, Allen key and steel bolt; the larger 13-Joule delivery list additionally names the extension and O-ring. Neither 13-Joule delivery list names a mounting screw separately.
These are component packages, so a marker, tuning barrel or HPA supply should not be assumed from the word “Starterkit.” The listed valve-and-pin components and bolt are already supplied in all four offers. In the two extended offers, the extension and its seal are already supplied as well.
For readers interested specifically in the individual 13-Joule Gen2 component, the HDP50/TP50 Gen2 PowerKit guide covers that smaller purchase. This comparison adds the complete package view: original version, bolt scope, extension scope and the output wording associated with each actual offer.
The four HDP50/TP50 Starterkit offers
Z-RAM StarterKit: Firing Bolt + Powerkit.50 V2 for Umarex HDP50 TP50, export valve, Gen2 + Gen1 , 7.5j version 20-30J
For the listed 7.5-Joule Gen1/Gen2 HDP50/TP50. Includes PowerKit.50 V2, black steel bolt, Allen key and mounting screw; Z-RAM describes 20–30 J depending on setup and temperature. Z-Extension is outside this delivery list.
View 7.5 J without extension
Z-RAM Starterkit: Firing Bolt + Powerkit.50 V2 + Z-Extension for Umarex HDP50 TP50, export valve, Gen2 + Gen1 , 7.5j version 25-35J
The larger 7.5-Joule Gen1/Gen2 offer adds Z-Extension and its O-ring to PowerKit.50 V2, steel bolt, Allen key and mounting screw. Advertised package output is 25–35 J with 35+ wording.
View 7.5 J with extension
Z-RAM Starterkit: Firing Bolt + Powerkit.50 for Umarex TP50 HDP50 13J Version | GEN.2 | Exportventil | 20-30 J+
The 13-Joule Gen2 combination lists PowerKit.50, steel bolt and Allen key, with advertised 20–30 J+ output. Its scope is the bolt-and-PowerKit package, without Z-Extension.
View 13 J without extension
Z-RAM Starterkit: Firing Bolt + Powerkit.50 + Z-Extension for Umarex TP50 HDP50 13J Version | GEN.2 | Exportventil | 25-35 J+
For the 13-Joule Gen2 HDP50/TP50, this 25–35 J+ advertised package includes PowerKit.50, black steel bolt, Z-Extension, its O-ring and an Allen key.
View 13 J with extensionThe shared firing bolt’s practical purpose
This Z-RAM presentation speaks about the HDR50 bolt-and-pin combination. The current HDP50/TP50 Starterkit pages identify the shared bolt, making the clip useful component context while the pistol-specific package determines the PowerKit choice.
▶ Play on YouTube🚀Easy installation #powerkit with #zram Firing-Bolt for #umarex #HDR50 #TR50 #HDP50 #TP50 #airgun 😎
Channel: Z-RAM
PowerKit components and the separate extension
Z-RAM identifies the PowerKit as a pin-and-valve combination, then names Z-Extension separately. That distinction helps explain the two package sizes; the clip does not compare their HDP50/TP50 output.
▶ Play on YouTubeUltimate Power Kit Explained: Boost Your Performance HDR50 TR50 HDS68 HDR68 Umarex
Channel: Z-RAM
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