[2] Pneumatic components are:
[5] The Valve Body Hole is on the bottom of the Valve Body. The On/Off Valve Assembly fits into the Valve Body Hole. At the bottom of the Valve Body Hole, placed in before the On/Off Valve Assembly, are two o-rings pressed within each other. The two o-rings prevent CO2 escape past the On/Off Pin and through the On/Off Valve Assembly. The inner of the two o-rings, the Valve Body Hole Small O-ring, is an active o-ring made of teflon. The outer of the two o-rings, the Valve Body Hole Large O-ring, is an inactive o-ring made of urethane.
[6] The On/Off Valve Assembly is used to control the flow of CO2 between the Regulator and the Air Chamber. The On/Off Valve Assembly consists of the On/Off Top, On/Off Bottom and On/Off Pin. Located in the Valve Body Hole and moved by the Sear, the up and down movement of the On/Off Pin seals the Regulator from the Air Chamber. To prevent CO2 escape, the On/Off Valve Assembly uses two o-rings. The On/Off Bottom Large O-ring is an inactive o-ring made of urethane. The On/Off Bottom Small O-ring is an inactive o-ring made of white teflon.
[7] The Air Chamber receives the measured charge of CO2 from the Regulator. When the Air Chamber vents, the CO2 gas expands through the Power Tube and pushes the Bolt forward. Level 7 paintball guns have slightly larger air chambers than previous models to decrease the pressure within the chamber and reduce paintball breakage. In Level 7 paintball guns, the Power Tube is welded to the Air Chamber. The Air Chamber cannot be opened.
Regulator
[8] The Regulator is the heart of the 68AUTOMAG. The Regulator, as
the name implies, controls the pressures within the 68AUTOMAG
and therefore the velocity.
[9] The Regulator Body is at the rear of the paintball gun and screwed into the Valve Body. The air seal is maintained between the Regulator Body and the Valve Body by the Regulator Seal and the Regulator Body O-ring. The Regulator Valve with the Regulator Valve Spring is used to close the Regulator from the Air Source. Located on the bottom of the Regulator Body, the Regulator Body Detent Pin is a small metal pin which slides into the Z-shaped Slot in the Rail. The Regulator Body Detent Pin is designed to prevent the Valve Body and Regulator from springing back clear of the Rail when the Field Strip Screw is removed.
[10] The Regulator Piston is inside the Regulator Body. The position of the Regulator Piston is adjusted by turning the Regulator Nut which compresses the Regulator Spring Pack. By moving the Regulator Piston, the pressure of the CO2 in the paintball gun and thus the velocity is controlled.
[11] The Regulator Piston also contains the Blow Off Valve. The Blow Off Valve vents off any overpressure in the Regulator or Air Chamber. The Blow Off Valve is factory set for approximately 550 psi and is not user adjustable. If fired when venting, at the factory pressure setting, the paintball gun is firing at approximately 340 fps, an unsafe speed.
Power Tube
[12] The Power Tube delivers the blast of discharged CO2 from the
Air Chamber to the Bolt. The Power Tube contains the Power
Tube Spring and the Power Tube O-ring. The Power Tube Spring
holds the Power Tube O-ring in place to seal the Air Chamber.
[13] The Power Tube Insert is made of brass and screws into the Power Tube. The Power Tube Insert is open on the end which allows the central shaft of the Bolt to slide into the Power Tube, through the Power Tube Spring and against the Power Tube O-ring to complete the seal on the Power Tube.
Bolt
[14] Held in place by the Sear, the Bolt sits overtop the Power
Tube and blows forward when the paintball gun is fired. The
central metal shaft of the Bolt slides into the Power Tube to
seal the Power Tube from the Air Chamber until the paintball
gun is fired. Because replacing a bolt is easier than a
sear, the Bolt is made of a softer material than the Sear.
Eventually, the Bolt will wear along the edge where the Sear
rests. A worn down edge will prevent the Bolt from locking in
place and the paintball gun will go fully automatic.
Foamie
[15] The neoprene rubber Foamie is designed to cushion the
paintball as it is pushed past the Nubbin into the Barrel by
the Bolt. The Foamie is the only part of the paintball gun
that will require regular replacement (generally once a
season). The Foamie is glued to the front of the Bolt using a
commercial super glue.
Bolt Spring
[16] The Bolt Spring is made of high tensile square spring steel.
A squared spring was chosen to help in seating the Bolt Spring
onto the Bolt. Installed over the Bolt, the Bolt Spring
compresses as the Bolt moves forward. When the CO2 escapes
the Bolt, the Bolt Spring expands and pushes the Bolt back to
where the Sear can catch the Bolt.
Back Bottle Adapter
[17] The Back Bottle Adapter is attached to the rear of the Rail by
two screws and is the attachment point for the CO2 source. It
is also used to deliver lubrication to the internal components
of the paintball gun.
Air Hose
[18] A braided metal Air Hose delivers CO2 from the Back Bottle
Adapter to the Valve Body. An external hose was chosen so
that the design of the 68AUTOMAG did not require an internal
CO2 delivery passage. An internal CO2 delivery passage would
require constant resealing when the paintball gun was broken
open for maintenance. The Air Hose is connected by brass
fittings that remain sealed during normal maintenance. This
limits the chances of a leak from the Air Hose.
Air Source
CAUTION
Do NOT use a siphon type constant
air tank. Liquid CO2 will damage
the seals and o-rings.
[19] The 68AUTOMAG can be used with any standard source of CO2 either constant air tank, 12 gram or back bottle pack, provided the source can be attached to the paintball gun. The Air Source used must be able to feed CO2 fast enough into the 68AUTOMAG to support rapid firing.
O-rings
[20] The O-rings used in the 68AUTOMAG are all made from either
high quality 90 durometer urethane or teflon. The O-rings are
designed for long life and abrasion resistance. The O-rings
were selected for easy access and interchangeability.
[21] O-rings are classed as either active or inactive. An active O-ring continuously seals and releases CO2. An inactive O-ring only continuously holds CO2 pressure.
[22] All active O-rings are accessible without tools, still, removing the O-rings without a tool may be difficult. If a particular active O-ring starts to wear and a replacement is not available, the active O-ring can be exchanged with an identical inactive O-ring from another portion of the paintball gun. It is highly unlikely that inactive O-rings will ever wear or leak, but, they can be traded with their identical active counterparts on the field if necessary. Swapping a leaking inactive o-ring into an active position is not recommended since active o-rings are critical to the paintball gun working correctly.
Barrel
[23] The standard Barrel on the 68AUTOMAG is made from aluminum
stock. The Barrel Lock Pin is a stainless steel detent pin
mounted in the Rail. The O-rings on the Barrel serve to give
the Barrel a friction fit. The Barrel O-rings do not seal air
pressure.
Nubbin
[24] A wire Nubbin prevents double feeding. The Nubbin is woven in
a machined channel on the barrel upper surface and held in
place by the Barrel O-rings. A properly installed Nubbin
protrudes about 1-1/2 to 2 thicknesses of a matchbook cover
into the breech of the Barrel. The Nubbin will automatically
compensate for all size paintballs and should give long life
if not abused.
Loader and Elbow
[25] Included with the 68AUTOMAG is a 90 round VIEWLOADER and
Elbow. Under ideal conditions, the Loader provided can feed
paintballs at a maximum rate of seven per second. The plastic
Elbow connects the Loader to the Ball Feed Tube on the Main
Body. To permit maximum feeding, the Elbow should be smooth
on the inside and without sharp edges or corners. Any
obstructions will cause the paintballs to hangup in the Elbow
and Loader.
Paintballs
[26] There are many brands of paintballs on the market; all with
different specifications. Differences in shell thickness,
shape, fill colour and fill density will result in performance
differences. Low quality paintballs will work poorly in the
68AUTOMAG. With a properly set up paintball gun using quality
paint, users can expect to break only three to four paintballs
per thousand. Low quality paint will break one in 50.
[27] Paintball breakage is caused two ways: poor feeding or impact. Poor feeding will result in the paintball not being fully in the breech and the bolt cutting the paintball during firing. Impact comes either from the bolt or from CO2 blast. When the Foamie is damaged or missing, the Bolt will break the shell of the paintball. Blast from the CO2 will break thin shelled paintballs.
[28] A good test for paintball shell strength is to drop a few paintballs, one at a time, from a height of six feet. Paintballs that consistently survive six or seven bounces are considered fresh. Paintballs that break within three bounces are either stale or have weak shells.
[29] If the Foamie and the Nubbin are in good shape and the paintball gun still experiences breakage problems, switching paintball brands or colors within a brand may solve the problem because the paint batch has changed. Experimenting with different type of paintballs and colors will decide the best paintball for each individual 68AUTOMAG and playing conditions.
Accessory Rails
[30] There are two Accessory Rails molded into the side of the Rail
for mounting various accessories. The Accessory Rails can
hold anything that would bolt to a regular sight rail.
[32] Regulation begins when an Air Source is connected to the paintball gun and the pneumatic system builds up pressure. At a predetermined pressure, set by the Regulator Nut, the Regulator Valve closes and seals off the Air Source from the remainder of the paintball gun. The pressure in the paintball gun is now approximately 400 psi though the air source pressure may vary from 600 to 1000 psi under different temperatures depending on the air source used.
[33] Chamber Fill, the second stage, happens when the Trigger is released. The On/Off Valve Assembly opens and allows the Air Chamber within the Valve Body to fill from the Regulator to a regulated pressure of 400 psi. To prevent flow into the Power Tube, the forward seal of the Air Chamber is created by the Power Tube O-ring and the central shaft of the Bolt.
[34] Stage three, Chamber Dump, is the critical phase. The air chamber design is like a champagne bottle with a cork stuck in the opening. The Bolt, like a cork, wants to pop forward, but the Sear holds the Bolt in place. Pulling the Trigger pushes the Trigger Rod which tilts the Sear. The Sear first closes the On/Off Valve Assembly shutting off the Air Chamber from the Regulator. This gives the paintball gun a precise amount of regulated CO2 charge within the Air Chamber. The Sear next releases the Bolt. The CO2 pressure pushes the Bolt forward and breaks the forward seal of the Air Chamber. Like a cork moving out of the bottle, the Bolt starts moving forward into the breech area. The Bolt pushes the paintball past the Nubbin into the Barrel. As this has been happening, CO2 has been entering the Power Tube, expanding and moving through the Power Tube Insert and the front face of the Bolt. The escaping CO2 blows the paintball down the Barrel and out into the atmosphere. As the Bolt moves forward, it compresses the Bolt Spring located in front of and around the Bolt. After all the CO2 escapes the Bolt, the Bolt Spring expands and pushes the Bolt back into the starting position where the Sear locks the Bolt down again and reseals the Power Tube from the Air Chamber. Releasing the Trigger begins the process again by opening the On/Off Valve Assembly and filling the Air Chamber from the Regulator.
Using Pressure Regulators
[36] All pressure regulators, by the nature of their design, cannot
fill a chamber instantly. Regulators must fill most of the
chamber quickly then taper off to reach the desired pressure.
Chamber Fill on the 68AUTOMAG takes roughly 1/3 of a second.
Because of the Regulator tapering off, when firing the
paintball gun faster than three shots per second, the Air
Chamber will not fill fully and the average velocity will drop
by 10 to 20 fps.
Using CO2
[37] The other problem revolves around the CO2 itself. Usually
thought of as either a gas or a liquid, in reality CO2 takes
the form of steam. Like water, CO2 boils when heated and
becomes a steam. The CO2 steam will still exist in a moist
form until its temperature is above 87 F (31 C) at normal
atmospheric pressure. Boiling temperature of any liquid is
affected by the pressure; higher pressures raise the boiling
temperature, lower pressures lower the boiling temperature.
Firing rapidly lowers the pressure in the Air Source and
causes the CO2 to boil at a lower temperature than normal.
The CO2 steam then enters the Air Chamber. The Air Chamber
empties when the paintball gun fires and lowers the pressure
yet again. The steam in the Air Chamber boils into a gas and
expands its volume by 30 times. The result is velocity
variation in firing the paintballs. Placing a warm Air Source
onto a cold paintball gun will allow warm CO2 steam into the
paintball gun where the steam will condense into a liquid in
the Air Chamber. When the Air Chamber empties, the liquid
rapidly boils off and results in a dangerous overspeed shot
(See Part 1, Para 11.).
Cold Weather
[39] 68AUTOMAG performance at temperatures below 40 F (4 C) will be
poor because gas pressure is affected by temperature of the
gas. Since the paintball gun is designed to function at a
predetermined pressure, temperatures below freezing will not
generate sufficient air source pressure for adequate
velocity. Some method of keeping the Air Source above
freezing will be necessary, but this increases the risk of
warm CO2 condensing in the cold paintball gun and dangerous
overspeed shots.
Rate of Fire
CAUTION
Rates of fire higher than 6 shots
per second may result in feeding
problems. The standard
VIEWLOADER supplied with the
paintball gun can only feed 7
paintballs per second under ideal
conditions.
[40] The average person can fire 4 to 5 shots per second due to the 68AUTOMAG trigger mechanism. The trigger mechanism was designed for the highest rate of fire possible. Trigger takeup, the distance the Trigger is pulled before moving the Trigger Rod, has been kept to a minimum. Charged with adrenaline in a game situation, a person may increase their rate of fire to 6 shots per second.
[42] Updates are changes that improve the original design or function of the paintball gun. For one year from date of purchase, Airgun Designs, Inc. will provide to registered owners free updates.
[43] Upgrades are options that add new features to the original design. A few examples are specialty barrels, differing air hose lengths, front bottle adapter kits, left feed main bodies and power feeds. Upgrades are available from the company at a reasonable cost.
[44] Contact Airgun Designs, Inc. at (708) 520-7507 or Fax (708) 520-7848 for information on the latest updates and upgrades available. If sent a self addressed stamped envelope and the serial number of the paintball gun by the owner, Airgun Designs, Inc. will return a complete history of that particular 68AUTOMAG.