Excalibur is a pump-action blaster with plenty of power, quick spring swapping, and the ability to swap between full length darts or half length darts on the go!
Changelog is at the bottom of the description text.
Most recent update: 7-9-2025.
Blaster Overview:
Firing Demo:
Reviews:
There is a full written assembly guide (with photos) for Excalibur, available as a PDF download in this Printables file repository :)
Here's some info about Excalibur:
Excalibur has a 120mm long prime, with ball bearings used to stabilize the priming system, to make everything buttery smooth.
Excalibur works with both full length dart magazines, AND Talon half length dart magazines (using an easily removable adapter piece).
This means that Excalibur can use Nerf N-Strike/Elite magazines, DartZone full length dart magazines, X-Shot full length dart magazines, and pretty much any other magazine compatible with Nerf Elite magwells.
The plunger spring can be swapped easily via a twist-lock quick access spring door in the stock!
Quick barrel swaps with just 1 screw on the bottom of the blaster to loosen and take out the barrel.
Excalibur uses a printed chamber piece that the ram seals into, which then itself seals against the barrel. This allows for some nice quality of life features, such as:
There is a tightening ring that prevents darts from falling out of loose 0.527"ID barrels
The chamber seals much better with the 3d printed ram that this blaster uses
and the printed chamber removes the need for chambered metal barrels on this blaster (vs something like a Talon Claw or Caliburn). This thing takes unchambered barrels just fine!
As previously mentioned, this blaster uses a printed ram, which in this case helps with feeding a wider array of darts, and it also happens to reduce the per-hardware kit cost by a nice chunk!
Full front to back aluminum bar construction, with a bar tensioner, to keep everything extremely sturdy and rigid.
A ball detent is used to keep the ram/priming system in the forward chambered position when moving between cover, so the breech doesn't swing open and flop around.
Center and outer plunger spring guiding geometry, so the spring doesn't kink and bend too much during the prime (so it's smoother).
Flared magwell for speedy reloads.
Compatible with Caliburn length springs (k31, 788, k25).
The way I've designed the front end of this blaster allows it to use pretty short barrels, down to 10" long if you want it to reach the muzzle, or technically even shorter if you don't mind the barrel sorta floating inside the barrel shroud.
Note: If you want to attach a SCAR barrel, I recommend using a 12" barrel, or 11" if you use a thin style PCAR (like a Worker SCAR or a Thanhtacles WhiskerSCAR).
(Note for storage of the blaster: When setting aside Excalibur, the bar tensioner should be loosened for storage. This will let the parts relax in storage. If stored fully tensioned, some of the printed components might become fatigued over time.)
For full length darts in this blaster, I recommend against using wide headed darts such as waffles or Nitroshot darts.
Inside sealed barrel blasters (like Excalibur), wide headed darts tend to get caught up or jammed inside the breech and barrel. They also REALLY DO NOT WORK with SCAR attachments.
Thinner headed darts, like Nerf Elite darts or Worker full length darts, tend to work way better.
Excalibur has several different options of front barrel shroud to choose from, to customize the aesthetic of your blaster.
Plain/Blank (smooth with no patterning)
Pattern: 2-3-2
Pattern: Split Trapezoids
Pattern: SwordBladeCutout1
Note: This shroud has a full cutout gap in it, so it might have issues with grabbing onto fingers, hair, clothing, etc. This piece has not been tested in person yet at the time of writing (6-29-2025).
Other parts:
There are two Chamber options for Excalibur!
The Wide chamber is the default recommended chamber. It works well with full length darts, half darts, and it should handle worn darts just fine.
The Narrow chamber is specifically made for higher FPS users, who only use half length darts, and mainly use fresh/good condition darts. This chamber is tighter, which gives a slight boost to FPS with the correct darts. But because it is tighter, it does not work well with full length darts or worn darts.
There are two versions of the grip. One has the little “shoe” at the bottom, and the other does not. Choose whichever one you prefer :)
There are two versions of the SpringDoorPlug. One matches the contour of the stock, and the other has two finger grabby bits which make it easier to twist when swapping springs.
Also, there are STEP and F3D source files available for you to customize the blaster even further yourself!
Filament usage estimates (PLA filament) (Also includes supports and brims for recommended parts.):
All parts together: 1275 grams of filament
Green: 768 grams
Orange: 315 grams
Black: 192 grams
All STLs are exported in their correct print orientations.
There is a .3MF file for Bambu Studio, with all the parts in each folder laid out on plates, in their correct orientation, and with correct infill/wall/support settings.
Minimum print bed size information:
All of these parts should fit fine in a minimum150mm x 150mm x 150mm print volume.
The tallest part is 128mm tall (BarrelShroud_Front).
The longest/widest part is 185mm long, but you can put that one diagonally across a build plate (Picatinny Rail).
The “default” print settings for this blaster are 20% infill, 5 walls (I personally use Gyroid infill pattern). Parts with different settings will have those settings marked in bold text.
There is a full written assembly guide (with photos) for Excalibur, available as a PDF download in this Printables file repository :)
Its really good, go download it.
There's good text and picture instructions for every aspect of assembling Excalibur!
Notes:
Make sure ALL the supports are removed from any parts with supports.
Remember to remove the built in supports from the picatinny rail dovetails.
(Note for storage of the blaster: When setting aside Excalibur, the bar tensioner should be loosened for storage. This will let the parts relax in storage. If stored fully tensioned, some of the printed components might become fatigued over time.)
Disclaimer: This is not a toy. This blaster is meant for hobbyists, not children. Blaster must be operated correctly to avoid injury. I am not responsible for any injuries from this blaster. Please use a bright/blaze orange muzzle and barrel cap on this blaster. Consult local laws before building this high powered blaster.
Changelog:
6-30-2025: Release
7-9-2025: I added the STL for a new optional version of the spring door plug which has wider finger grabby bits, to hold onto it more easily during spring swaps.
Sillybutts
