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.
Although the Xpower breech system doesn't feature a 100% air seal (air still escapes around the funnel connection area), its possible to compensate for this by using stronger spring loads to achieve optimal ranges (see below for comparison tests and modding tips).
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 features a full air seal, while the funnel design of the Xpower breech is simpler and much easier to install, but it has a partial air seal, hence resulting in 15-20% shorter ranges at equivalent spring loads.
The solution is to install stronger springs with the Xpower breech (20-30% stronger) to compensate and provide more power to the system.
A good example is the 12kg spring that Dninja (aka Heng) at Xplorer demonstrated during his development of the kit. Here is the video of his range test with the 12kg spring:
With his 12kg spring, the kit achieved 100+ ft ranges too, so that's the spring load users should install if they are looking to get optimal ranges.
Note that when using heavier spring loads, the system will naturally undergo higher stress and wear. In addition, the motor will also draw higher amp current, so battery sources may tend to drain abit quicker than with lighter spring loads.
:: 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