Friday, July 20, 2012

Xpower Stampede Kit - Review & Installation Guide!

Check out the Xpower Stampede Kit from Xplorer!

Xplorer is a company in Singapore that designs and produces ready-made aftermarket performance parts and kits for Nerf blasters.

The Xpower Stampede Kit upgrades the stock Stampede breech system to an improved breech design that enables more efficient air flow from the plunger to the barrel, hence generating more power and longer ranges.

The parts in this kit are individually CNC machined from a multi-axis milling machine and further hand finished to ensure high quality and fitment.

:: Overview ::

This kit comprises of just 2 main parts, the Xpower receiver piece (with attached copper barrel) and the Xpower bolt tip piece.

The included copper barrel is 12cm (approx 4.7") in length and designed specifically to fit stefans (custom foam darts), the dart fit is similar to 9/16" K&S brass barrels or 0.528" ID PETG barrels.

The Xpower system works by utilizing a funnel design in the receiver. When chambering a foam dart, the bolt is guided into the receiver funnel as it moves forward and pushes the foam dart securely into the barrel, then the Stampede fires and the bolt retracts back. This completes one firing cycle.

In the photo below, you can see the funnel design in the Xpower receiver.

In order to connect into the funneled receiver, a matching Xpower bolt tip piece will be installed on the existing bolt to enable this system to work.

Note that the Xpower Stampede breech is designed for short-length stefans (up to 3.5cm length), this is to ensure high performance, consistency and accuracy.

This kit is designed to be very simple to install and can be done by anyone with basic modding skills.

:: Installation Guide ::

For the system to work optimally, ensure that the Stampede is already modded with the various basic AR removal, aftermarket spring and voltage increase mods beforehand, as shown in my Nerf Stampede Mod Guide.

Proceed to remove all the original parts and mechanisms from the front of the blaster.

Step 1: Start with the receiver section.

Slot the Xpower receiver and copper barrel into the original orange plastic barrel, use some electrical or duct tape to wrap a few ring layers around the copper barrel so that it sits properly within it. Install the 3 machine screws to secure it to the casing.

The receiver section is done!

Step 2: On to the bolt section.

Take the original orange plastic bolt and draw guide lines across the front part of the bolt tip, note where the dotted guide lines are drawn in the photo below.

Also draw a guide line at the top of the bolt to indicate the bolt tip alignment.

Use a Dremel with a cutting wheel and sanding bit (or other suitable cutting tool) to cut the bolt tip at the guide lines. Make sure the cut is clean and sanded smooth.

Glue the Xpower bolt tip to the original bolt. Ensure that it is aligned accurately. Use high strength glue to ensure a durable bond.

The bolt section is done!

Step 3: Install all the parts into the Stampede.

Test the bolt movement to ensure that the Xpower bolt tip chambers into the Xpower receiver smoothly and is also able to retract back automatically on its own without resistance.

After everything is assembled. This is what the Xpower Stampede breech will look like.

The Xpower Stampede Kit works with both the Xpower 12-dart Stefan Clips (Version 2 Only) and Converted N-Strike 18-dart Stefan Clips.

:: Demo & Test Fire ::

In this demo & test fire of the installed Xpower Stampede Kit, i am using a combination of 9kg load spring with 16.8V power:

Note that the Stampede's range and rate-of-fire will vary depending on the spring load and power source/voltage. Users can customize it to their own preference.

:: Comparison Tests & Modding Tips ::

Many modders have been asking about the difference between the Brass breech and Xpower breech for the Stampede.

Here is a comparison test video that demonstrates the performance difference between both breech designs, based on equivalent spring loads and optimization mods done:

Note that this comparison test is not meant to establish which design is better, its just a process to understand their differences and how to optimize them. There are pros and cons to both designs (beyond just range distance), so its up to users to determine the most suitable design for their usage.

The variation in their ranges are due to the characteristics of their different breech designs.

The brass breech design is more complex and requires skill to build and tune but when built well it features a full air seal, while the funnel design of the Xpower breech is simpler and much easier to install, but sometimes there may still be tiny gaps in the seal, hence resulting in slightly shorter ranges at equivalent spring loads (each setup is different due to parts variations, so it may just need further fine-tuning to get a full air seal).

:: Summary ::

Overall, the Xpower Stampede kit is an ideal aftermarket performance enhancement for modders who are looking for high quality ready-made parts. It saves alot of modding time and requires minimal installation work.

For non-modders, this kit grants instant improvement to their blasters without the need to spend hours modding and tuning. Xplorer also offers their customers installation services for the blaster kits too (subject to their technical staff manpower availability).

With the right spring load and setup, the Xplorer Stampede kit offers users excellent modded performance and greatly enhances the effectiveness of their Stampedes. :)

To order the Xpower Stampede Kit: Xplorer Web Store

To participate in Xpower discussions: Xplorer Facebook Group


  1. They should really make it airtight.... they said they only made 50 of these.. so mabye the version2 will be airtight.

    Does it have any advantage for no being airtight? like does it have a higher ROF? i alwasy thought the airtight design of a brass breach would put more strain on the motors than probably the stronger springs in the Xpower would.. as moving brass over the top of its self is alot of friction esp with the lip you make. hmmmmm

    Perhaps They need to create a rubber fitting or condom style thing for the dart pusher of the Xpower stamped so that it can be air tight... and easily to replace the airtight seal.

    The brass breach system will eventually not be air tight due to metal bending over time. Any tru airtight system needs a replaceable element

    1. Anonymous,

      Well... when a breech is not fully 100% air-tight, air from the plunger will escape out of the breech gaps during firing, this results in comparatively lower ranges (at the same spring load) due to the loss of pressure propelling the foam dart.

      Whether a breech is air-tight or not doesn't affect the RoF noticeably, its the power of the shot that is affected.

      For brass breech systems, the K&S brand brass tubes used are made in such high precision that they can slot over each other without resistance (ie. if you slot a 17/32" brass tube into a 9/16" brass tube, then hold them even at a slight angle, the 17/32" brass tube will just slide out smoothly on its own), yet they can get a 100% air seal... but this feature requires precise alignment of both tubes to achieve this effect.

      Modders who have worked with brass breeches will be very familiar with this unique characteristic of the K&S brand brass tubes.

      In my brass breech design, i use a PVC guide cover system to ensure the brass bolt and barrel are kept in perfect alignment during operation, the bolt to barrel overlap during connection and firing is only 2-3mm, so every shot has perfect air seal with no resistance (this is why a brass breech requires more work to build, it has to be made properly and tuned to perfection).

      For the Xpower system, i guess their challenge is to find ways to improve the air seal of their breech design but yet not end up with too much resistance in the process (or the breech may get stuck), it is a delicate balance so hopefully they can find suitable methods to improve the design further.

      But in its current version, the Xpower breech already works as intended, its main advantage is its simplicity and ease of installation (no need to spend hours building or tuning it, ideal for non-modders or those with no time to mod)... the flip-side is users just need to use 20-30% stronger springs to compensate and get optimal ranges.

      Btw, i do agree that materials in any system will need to be replaced when they wear out too (everything has a service life).

      Just for modding reference, to date i've been using my brass breech Stampede in more than 20+ full day Nerf games over the past 6 months, and each time firing an average of 300+ shots throughout each game (its actually quite conservative for a Stampede user, haha), so that's around at least 6000+ shots fired so far, and the breech is still 100% air tight... so the brass material reliability has been pretty good so far.

      But if there is a need to change the worn out parts eventually, all it requires is just a simple swap of the brass tubes (costs only a few dollars). :)

    2. Okey cool ... i just had a memory of you using a pipe cutter to make a indent lip on one of your brass mods to "jam" the brass together so it would make a tighter seal. After going back and looking at the Stamped brass beach mod guide i noticed it was not apart of it.. must have been for another mod. My mistake. Perhaps you could help Xpower with future designs :) Beacuse just as we mod Nerf we could mod Xpower too just with the added bonus of Xpower working with us more.

    3. Anonymous,

      I guess you are referring to the "tightening rings" mod on the brass barrels in my Longshot brass breech mod guide.

      The tightening rings are made to narrow the barrel slightly to grip thinner foam darts (not to "jam" the brass together). It doesn't affect the bolt to barrel seal... its just meant to hold foam darts better in the barrel. :)

  2. yes i was thanks for info :)

  3. Are you guy Excited? well you should be!!
    you almost have 2 million page views!!! good job people over at SGnerf!!

  4. I do not have my Xpower Stampede kit yet but I do have an Xplorer Longshot kit which uses the same system and have found that after firing darts which are slightly too large OD that have jammed in the barrel the breech does not have a 100% air seal but it still makes a very good seal and takes some 2-3seconds for the plunger to come to rest. I would say it has a 90% seal.

    1. Anonymous,

      Yes, that's what i experience with the Longshot Xpower Kit too, i have both the 1st generation (aluminum barrel) and 2nd generation (copper barrel) versions.

      The Longshot Xpower Kit does have a pretty good seal, and combined with the Longshot's larger plunger air volume, the effect of its partial air seal is minimized so it still gets optimal ranges.

      For the Stampede Xpower Kit, its plunger air volume is smaller so the effect of the partial air seal is more noticeable, hence the solution is to just use stronger springs to offset the difference. :)

      Note that loose barrel fit stefans are usually recommended for such partial air seal breech systems to get optimal results.

      If snug or tight fit stefans are used, once the air flow faces resistance it will end up exiting out of the breech gaps, as air tends to automatically escape out via the path of least resistance.

  5. Should I use a 12 or 13 kg spring with this kit? And what how many volts would need for a fast rof?

    1. Anonymous,

      From tests so far, 12kg spring is recommended for this kit to get 100+ ft ranges.

      16.8V from 4 x fully charged unprotected TrustFire batteries is the optimal voltage for fast RoF and reliability.

    2. Where could I find a 12kg spring?


    3. Check directly with Dninja Heng at Xplorer, he will be able to advise you on it.

  6. on your mod guide for the stampede you said 18v for 13 kg so wouldnt 16.8v not be enought for a 12 kg spring? would it be fater than stock rof?

    1. Anonymous,

      The 12kg load spring is slightly lighter load than the 13kg spring i tested, so 16.8V is still sufficient to maintain a faster RoF compared to stock RoF.

  7. I found a 5 aa battery holder for The trustfire batteries which would be around 20 volts. Would that be too much for a 12kg spring? Sorry for all the questions about voltage and kg I can't wait to own wars with this thing!

    1. Anonymous,

      You can just test and see if it works well for your setup... but do remember that with heavier spring load and higher voltage feeds, the motor and batteries will tend to overheat much faster, so it may affect their condition and reliability.

  8. i was wondering can you use this with normal darts because we can't use anything else in our games

    1. Anonymous,

      Nope, it can only use calibrated stefans (short length customized foam darts).

      To maintain high performance and accuracy, these type of breech systems are not designed to use normal foam darts.

  9. Help!

    I took my stampede apart to paint it and now it doesn't work right. The darts just fall out of the barrel. Any ideas?


    1. Anonymous,

      You'll have to open it up and re-assemble everything back again, make sure all the parts are install correctly, double check to confirm they are working before closing the casing.

      For your case, check that the dart paddle blocker (the mechanism in front of the clip well) is installed and working properly, that could be the cause of your issue.