(NTS)
Updated: 7/4/2006
NAVIGATION
SpecificationsLinks Photos
The BS-9 is a magazine-fed slide-action pistol capable of over 90 feet in range with a high rate of fire. The pistol is cycled by racking the slide which chambers a new round while cocking the plunger at the same time. The magazine is fixed and is loaded through a port in the rear of the magazine inside the trigger guard. To load the pistol you depress the magazine follower by pulling on the the loading rod that protrudes from the right side of the magazine. Once fully depressed the loading port is opened and darts can be inserted through the port into the magazine. Once the magazine is full, the follower is released and the slide can be racked to ready the pistol to fire.
The BS-9 utilizes much of the proven concepts of the BS-8 and BS-6. But it also incorporates some new ideas that will be discussed in further detail on this page.
In similar fashion to the SCAR, this pistol evolved from the GNS. The GNS turned out to be a fantastic sidearm. It has proved to be the most reliable of all my homemades and has very impressive ranges. Although very practical for battle the GNS is still a single shot weapon. Upon firing you must manually reload a dart into the barrel and cock to fire. The remedy to this shortcoming is to integrate a magazine for quick single action reloading. Because nerf darts must possess some length to remain stable in flight, locating the magazine in the grip is impractical. Also the nature of a spring plunger setup makes it difficult to locate the magazine that far to the rear without relocating the plunger system.
The BS-9 carries the designation "Nerf Tactical Sidearm". I like having the word tactical in the designation because the improvements and features all combine to make the weapon more effective in battle. The pistol can hold 5 rounds when fully loaded making it functional as a primary weapon rather than just last resort. Brass is used for the barrel and bolt making improving range and seals. The barrel is longer than on the GNS and ranges are extended. The overall length is slightly longer allowing for a larger site radius and more accurate shooting.
The BS-9 like the SCAR was designed almost fully in a CAD enviornment before any construction was performed. The final design for the pistol is shown below.
A number of innovations were integrated into this pistol from the get go. The pistol is designed to be slide operated meaning racking the slide will charge the plunger and cycle a round. A bolt breach system is used to accomplish this. The section of brass used for the barrel has a half section cut out of it. Another larger section of brass is used for the bolt and passes over the barrel to close off the open section. The slide is connect directly to the bolt and as the slide moves rearward the bolt does to. The rear face of the bolt pushes the plunger back to the catch. When fully racked the plunger engages the catch and the breach is open. A dart is pushed into the barrel by the mag spring. The slide is then moved forward and the bolt seals off the barrel and the pistol is ready to fire.
I always disliked the section of the plunger that protruded out the rear of the GNS when cocked and even uncocked. My initial design utilized a plunger that had minimal shaft. There is no shaft that continuously rides through the bushing in the rear. Instead the plunger is stabilized by an outer sheath portion that rides over the spring. There is still a portion of plunger shaft remaining to deal with the catch. This portion of the plunger would enter the spring perch and engage the catch. This style of plunger would be extremely light and result in no protrusion from the pistol either cocked or not. The issue with this kind of plunger is the catch face. There is no way to index the plunger so an axisymmetric catch face must be used. Similar to the FAR.
I intended to use this style plunger and even built the plunger. For some reason I didn`t feel like dealing with axisymmetric catch face requirement as there were plenty of other hurdles to deal with. I also didn`t think I could do the catch face to be strong enough and fit in the space necessary.
The resulting plunger is more traditional and very similar to the GNS. The plunger is indexed through the assembly screws as in the GNS. Because the slide is used to pull the plunger back the plunger shaft could be flush with the receiver when uncocked. So it wasn`t a total loss as the plunger only protrudes when cocked and even so it's only three inches. Ompa successfully utilized the shaftless plunger in his manifestation of the BS-9. I am gald someone used the idea and it works.
Ordinary PVC piping is the main material used in the construction of the NTS . The sizes used are as follows:
1" 200 psi PVC (Receiver)
1" SCH 40 PVC (Frame, Pistol Grip)
1/2" PVC Couplers (Barrel spacers, Spring Perch)
1/2" PVC (Spacers)
1/2" CPVC (Plunger Shaft)
Brass
17/32" Brass (Barrel)
9/16" Brass (Bolt)
Some other special PVC fittings were used in certain situations. For situations where a flat surface was required 1/8" lexan was used. To space the PVC pieces inside one another, I used electrical tape. This works extremely well and can produce extremely tight fits. I personally use CA glue (aka superglue) to due all the bonding involved. It adheres extremely well to both PVC and balsa. The advantage is the near instant drying time. CA will hold just as good as PVC cement. For assembly I used 1/2" #6 pan head sheet metal screws. These are just the right length to penetrate from the outside of the 1 1/4" PVC to the 1/2" PVC of the barrel but not penetrate the inner wall of the 1/2" PVC. They are very common and can be picked up at Walmart. The last major materials utilized in the were music wire and brass tubing. These two were used in conjunction at all pivot points. Music wire was also utilized for retaining pins, pushrods, etc. See the materials list in the plans for a more detailed list of materials
Barrel
The barrel is a section of 17/32" brass and has an effective length of just over 4 inches. The barrel is free floated from the front in a section of 1/2" PVC. This is to allow the bolt to pass over the barrel to seal the breach.
Bolt
The bolt is the key to the function of the pistol. It is essentially a section of 9/16" brass that passes over the 17/32" brass barrel. A section of PVC is located at the rear to allow for seal in the plunger chamber. The section of PVC is also where the operating rod connects to the bolt. The image below shows the bolt and the barrel assembly. You can see the hole where the operating rod connects to the bolt. A small section of brass is bonded to the from top portion of the bolt. This piece is to prevent binding as the pull from the slide through the operating rod is not inline with the movement of the action. This piece can be seen on the underside of the bolt in the picture below and can be seen better in the second image of the bolt only.
The operating rod connecting the bolt to the slide is offset to allow for the plunger cylinder portion of the receiver to remain sealed. The slot for the operating rod to pass through is located forward of the plunger section. The operating rod rides in a groove on the top of the barrel assembly.
Plunger
As discussed in the design portion of this page, the original design for the plunger was a shaftless design. I discussed the advantages and disadvantages of that plunger design above and also stated why I did not go with that design. The resulting plunger is more conventional and has a couple improvements over the GNS style plunger. The plunger head is made the same as on the SCAR with a single O-ring. The plunger is indexed through the side utilizing one of the assembly screws to dual function as the indexing pin as well. The GNS used a independent indexing pin. The catch face is a section of aluminum plate that passes all the way through the plunger. This allows for more positive engagement over the brass tubing style the GNS uses.
Receiver
The receiver is a section of 1" thin walled PVC. Like the rest of the guns the receiver is the portion that all other components bolt to. The image below shows the receiver with slide and fire control installed.
The slide is a section of 1/1/4" PVC that rides on top of the 1" PVC that makes the receiver. The iron sights are bonded to the slide. The operating rod is visible in the image below of the bottom of the slide. The operating rod is offset by about 3.25" to maintain a sealed section of the receiver for the plunger to ride in. It is bonded to the slide and engages the bolt through a slot in the top of the receiver.
The slide is held in place in the front by the operating rod. When installed the operating rod rides inside the receiver and is held captive retaining the slide. The rear of the slide is retained by two indexing screws that ride in slots in the slide visible above.
Frame
The frame is comprised of the pistol grip, lower receiver, magazine, and melee blade.
The magazine is fabricated through sterolithography (SLA). The same rapid prototyping technology used to fabricate the magazine well of the SCAR.
The image below shows the loading port on the rear of the magazine. The follower is depressed all the way to the bottom of the magazine opening the loading port. Darts are inserted through the port until the magazine is full. The follower is then released and the pistol is ready to go.
The magazine is bonded to the 1" PVC that makes up the lower portion of the pistol that houses the fire control group. The melee blade is fastened to the front of the magazine. The "blade" is made of 1/8" lexan and serves multiple purposes. It adds some structural rigidity to the front of the gun. It also serves as a mounting point for the front of the frame to the receiver. The rear of the frame is fastened to the receiver with two screws.
The magazine spring is custom made from music wire. It is bent to fit just inside the magazine well to minimize buckling. It engages the follower in the front through a hole. The follower fits loosly in the magazine well to eliminate bainding. To load the pistol the follower is depressed with the rod that extends out the right side of the magazine.
The two tangs that are visible on the melee blade engages slots on the receiver to retain the front of the frame to the receiver.
Fire Control
The fire control system for the NTS is almost identical to the system used on the SCAR and evolved from the system on the GNS. There are no real improvements in this portion of the design.
The image below shows the trigger plate for the NTS. Slightly different from the SCAR and the GNS, the actual trigger is part of the trigger plate. It is beefed up with a couple layers of lexan bonded to the aluminum. This increases trigger strength and reliability.
The magazine was the first component fabricated as it was the make or break component of this pistol. If the magazine was not going to work then there would be no pistol.
Materials List
<.xls Coming Soon>NTS Detail Drawings
<.rar Coming Soon> NTS Solid Model <.rar Coming Soon>The model was created in SolidWorks 2006. Due to the nature of SW, you must have SW2006 or later to open the files. You will not be able to open them with any version prior to 2006. The drawings are image exports from SolidWorks and can be opened like any other image. The materials list is done in MS Excel and is in .xls format.
Available for download are some videos showcasing specific points of the NTS.
COMING SOON
Nerfhaven Thread 1
NerfHQ Thread 1
All Image and Content ©
Evan Neblett 2006