CAD Modelling
Prototype Design Specifications
- Calibre: 5.5mm (.22)
- Ammunition: Paragon / Prometheus steel tip, plastic jacket
- Barrel: 480mm, one in 250mm twist
- Power Source: 12oz CO2 tank
- Magazine: 32 round or 50 round box / 200+ round helical
- Cyclic: 600+ rpm
- Operation: closed bolt delayed blowback, and bolt action
- Fire modes: Full auto, semi-auto, bolt action, single action trigger
- Length: approx. 1100mm incl. stock, excl. bayonette
- Construction: Steel, aluminium, brass, composite, wood
- Mass: approx. 5 Kg
Delayed blowback operation:
After more than a year of testing and development, a simple and effective
delayed blowback system has been designed. The system will work on the
basis of breech pressure, not allowing the bolt to open until the pellet
has left the barrel and the breech pressure has dropped. The advantages of
this system over simple blowback are the ability to operate at a wider and
higher range of pressures, true closed bolt performance meaning more power,
slower rate of fire meaning more control, and bolt operation occurring after
pellet is fired, meaning more accuracy.
Bolt action feature:
Bolt action fire mode has been incorporated into the design for sporting
applications. With bolt action mode, none of the propellant gas is diverted
to the cocking system and the cocking system remains stationary, thus
eliminating reciprocating masses and providing full power and accurate
firing. For each shot the gun will need to be re-cocked manually via the
charging handle. A small switch will allow quick changes between fire modes,
and will be separate from the automatic / semi-automatic fire selector.
Rigid Frame:
Unlike conventional break-barrels, the barrel will be fixed rigidly to the
receiver, thereby increasing accuracy.
True Assault Air Rifle:
There are a number of air rifle models produced that are marketed as assault
air rifles. Most of these are marketed on looks alone, and do not serve the
function of an assault air rifle in any way other than aesthetically. They
are either standard spring-air rifles re-packaged with pistol grips, or
underpowered double action BB pistols re-packaged to resemble rifles and SMG's.
When complete, this rifle's large capacity pellet magazines, bulk gas supply
and single action firing on demand, will make it a true assault air rifle.
Filled with technology:
A new trigger is being designed which will feature the mechanical feel
of a real trigger with a definite release point, but will trigger an
electronic circuit which will fire the rifle. The circuit may include
continuously variable valve timing and rate of fire control.
Ultimately, the trigger may be a combination of conventional and
electronic systems to allow functioning without power.
The new hammer and valve system to be incorporated will be unlike any
found in conventional air rifles. The new hammer and valve system will
reduce the maximum rate of fire slightly, but will open a high-flow valve
for longer, and require little effort to re-cock the system.
Status Logue:
24-04-05
Valve modified for incresed flow.
Pressure tested expansion chamber to 750psi.
Testing different bolt masses and springs.
30-04-05
Testing different valve shapes and sizes.
Valve seat changed slightly for better seal.
Gas seal grooves cut into valve.
30-05-05
Helical magazine test model created, design.
modified for better feed.
22-06-05
Magazine springs sourced.
Moulds made up for 32-rd single stack magazines.
Valve redesigned.
23-06-05
Bolt action fire mode via charging handle incorporated into design.
New valves machined from high strength steel.
20-07-05
Valve ports enlarged to 4mm each, with four ports per valve.
Firing mechanism tested on test bed with success.
Tests concluded that piston diameter could be reduced.
Software written to simulate performance of pressure regulator.
Regulator designed
CAD model updated for new full wooden / composite stock.
28-08-05
Box magazine cast and tested - will be milled in future.
Work commenced on building a bullet chronograph for testing.
11-09-05
Regulator pulled from design, hammer and valve redesigned.
Rifle construction on hold until full CAD model and drawings
of updated design have been completed. New hammer and valve to
be tested on separate big bore rifle.
Trigger redesigned for electro-mechanical operation, with real feel.
17-10-05
Design started on digital firing circuit for fire selection.
Further calculation / simulation software being written for modelling.
02-11-05
Side feeding magaine considered, computer modelled.
16-01-06
helical magazine showing rotor
Video
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