So I present the BS-8 Mk1 SCAR-N. From here on out I will refer to the rifle as the SCAR.
It looks a lot like the FAR. A good portion of it is very similar. The gerneral layout is similar with the upper and lower receivers and the receiver cover. Below is a comparison picture to show the differences. Side by side you can see how much smaller the SCAR is. The FAR looks massive.
Technical Specifications:
Description..........Carbine Assault Rifle
Designation.......................BS-8 Mk1
Release Date....................March 2006
Caliber..............0.54" (Micro Stefans)
Operation....Pump-action Rotating Bolt
Propulsion...................Spring Plunger
Magazine......Detachable Bottom Feed
Mag Capacity...............................11
Overall Length...........................28 in
Barrel Length............................12 in
Max Rate of Fire...................150 RPM
Max Range..............................110 ft
Effective Range.........................90 ft
Accurate Range.........................70 ft
Intended Use........................Primary
The SCAR-N is a pump-action magazine fed rifle firing 1/2" micro stefans. it is capable of 110' and accurate out to 70'. The box magazine holds 11 rounds and is removable. The rotating bolt lockup allows the rifle to be fired shellless by simply breach loading a dart of any length and closign the bolt.
Design
The SCAR resulted from my desire to improve on the deficiencies of the FAR. I wanted to fire micro stefans with this rifle and I also wanted to utilize brass for the barrel and shells. A long while back I discovered that 17/32” brass will fit into a standard AR15 magazine. For a year or more I have this section of brass stuck in a magazine. Eventually it occurred to me make shells out of brass and use an AR mag for a Nerf rifle.
The fast-action of the FAR is quick and easy to use, but grew old of the need to move your trigger hand off the grip to cycle the weapon. I decided to make the SCAR pump action which would allow for higher ROF simply because there was no need to move your hand.
A quick rundown of the features of the SCAR:
• Pump style action allows for higher ROF than the fast-action of the FAR
• Brass barrel for firing ½” micro stefans
• Brass shells. This allows for much smaller shells and in turn a higher magazine capacity
• Rotating bolt for lockup to prevent bolt bounceback
• Lightweight plunger: The plunger assembly has gone through an extensive weight loss program
• More rigid construction for higher durability
• More compact design for a compact weapon
• Ability to fire shellless
One problem I experienced with the FAR was shell seal. The seal between the shell and the barrel and bolt was held by the action spring alone. When the rifle is fired the bolt will bounce back slightly as the plunger hits home. This releases the pressure behind the dart and if the dart has not left the barrel yet will impede range. This led to some in consistency in ranges as different dart with different frictions would exit the barrel at different times. Ranges could range from 50-80 feet. If you have an exceptionally tight dart you could get some really pathetic ranges. This was pretty rare though. The solution to this problem was to have some kind of lockup for the bolt to prevent the bouncing. There are a variety of different systems for bolt lock. I decided to borrow another page from the AR15 and use a rotating bolt to lock it in the closed position. This involves a reciprocating bolt that move along a path defined by the bolt carrier. The bolt has lugs along its rim. These lugs engage a similar set of lugs on the end of the chamber. I will discuss this further when I talk about the bolt.
The bolt lockup led to another idea I wanted to implement. I wanted to be able to fire the rifle without shells. Because the bolt makes such a good seal with the barrel on its own, you can open the breach hand load a dart into the chamber and close the breach and fire. The performance is slightly less at maybe but there is no shell involved. This means that you can just pick up darts off the ground and fire off as if you had a modded Xbow or so. The ranges and ROF are still better than most.
Durability was anothar issue I wanted to address. The FAR had some balsa in it for flas surfaces. This has held up better than I expected but I have cracked the mag well walls a few times. Nothing a little glue won`t fix but it annoying and makes me cautious when I use the rifle. In the SCAR I replaced all the balse with lexan. The made the rifle much more durable and stronger. There is no balsa at all on the SCAR. I also beefed up the components that could be fragile. I used SCh40 PVC for the receiver cover which makes it rock solid now. The stock got special tratment to ensure its bonds with the lower receiver.
Components
There are a few more parts in the SCAR than the FAR. This is because of the lockup system and the pump action. But, many of the parts will look familiar.
Barrel
As I said above the actual barrel is made of brass. 17/32" Brass for firing micros. The barrel is a 12" section with the chamber attached to the end. The chamber is 9/16" brass so the shell makes a perfect seal when seated. The brass barrel insert is sheathed in 1/2" PVC to protect it. Electrical tape was used to position the barrel in the sheath.
As in the FAR the chamber is attached to the barrel. The barrel can be removed by removing hte assembly screws and pulling it out of the front. Only four screws fold it in. There is a section of the receiver fixed to the top of the barrel. This is done so that the pump slide can be removed after removing the barrel. that section of the receiver has the slide stop as well as the front receiver cover studs.
Edited by CaptainSlug, 20 November 2018 - 02:18 PM.
