AGD valves use a blow-forward design, where the force of air exiting the valve pushes the bolt forward and relies on a spring to return the bolt back to the sear. The valve assembly is broken down into 3 basic parts: The regulator (very back of the assembly), the on/off (middle part), and the powertube (front of the assembly).

A. Regulator

One of the unique characteristics of AGD's valve design is that it incorporates its own regulator assembly on the back end of the valve. AGD's markers do not need an additional inline regulator (and performance is usually hampered by adding one). The regulator (and thus velocity) is adjusted by turning the regulator nut on the very back of the assembly. Turning it clockwise increases velocity, and turning it counterclockwise decreases velocity. Each 1/8 turn equals roughly a 10fps change in velocity. After each adjustment to velocity, firing the marker about 10 times will allow the regulator to seat and give a more accurate fps reading.

B. On/Off

The on/off assembly essentially "separates" the valve into two halves. There are many variations of this part of the valve, but all of them use a center pin that is pushed upward by the back part of the sear, allowing the pressurized air from the regulator to enter the dump chamber.

Example of a an RT Pro on/off assembly:

C. Powertube

The powertube is pretty much like most other markers of this type: it controls the flow of air onto the paintball, and guides the bolt as it slides forward and back.

Firing cycle

Okay, now that we've covered the basic parts of the valve, let's put them all together and go through a firing cycle.

1. Air leaves the regulator, passes the open on/off, and fills the dump chamber.

2. Trigger is pulled. This does two things:

a. First, the rear part of the sear pushes the on/off pin up, closing the on/off and thus also closing the passageway from the regulator to the dump chamber.

b. Next, the front part of the sear moves downward, releasing the bolt.

3. The bolt pushes forward against the powertube spring, compressing it. Once the end of the bolt goes past the powertube o-ring, air is allowed to pass through the bolt and onto the paintball. Ball is propelled out of the barrel.

4. Powertube spring expands to push the bolt back to the sear.

5. Trigger is released. this does two things:

a. The front of the sear rocks up, allowing the bolt to catch and hold.

b. The rear of the sear rocks down, opening the on/off and allowing regulated air to again fill the dump chamber.

This animation shows the process of airflow through the valve with the Level 7 bolt installed:

These markers are very reliable, but as with anything man-made, sometimes need some TLC to get back in operating form. The most common issues involve leaking o-rings, and can be fixed in mere minutes. I'll list some of the most common symptoms and their related repairs.

1. Regulator leaks:

Symptom - Constant air leak out of the center hole of the adjuster nut.

Cause #1 - Adjuster nut is screwed in too far, and the valve is venting to relieve excess pressure.

Fix #1 - This venting is normal, and is resolved by unscrewing the adjuster nut to get the pressure back to a normal range. After every adjustment, fire about 10 shots to allow the regulator to seat. Check velocity and make sure it is within normal specs.

Cause #2 – The piston assembly inside the regulator is faulty and not allowing proper pressure regulation. (Usually accompanied by very high velocity.)

Fix #2 – Replace the piston assembly.

2. Level 10 tuning:

Once the Level 10 bolt is set up, it rarely needs anything but occasional oiling. However, sometimes more in-depth work might be needed.

A. Initial setup of the bolt - The kit consists of a new bolt, powertube tip, backing washer, 5 carriers, and a few shims. The hardest part of setup is choosing the right carrier and then determining if shims are needed, and if so, how many.

If possible, use a powertube o-ring that has already been broken-in. If you use a brand new one, it must be broken in by firing a few hundred times and then rechecked for carrier sizing.

1. Choosing the right carrier: Start with the largest size carrier and work your way down. Place the o-ring in it and slide it over the powertube shaft. The carrier must fit snug, but not too tight. An easy way to tell the correct fit is to hold the bolt vertically, with the carrier facing down. If the carrier slides off the shaft with no force, it is too large. Take the next size smaller and repeat the steps, always using the same powertube o-ring. When the carrier easily slides on the shaft but doesn't fall off when turned over, you've found the right size.

Generously oil it and install the bolt and valve. Air it up and check for leaks. Fire it a few dozen times and check for leaks. If it does leak, use your finger or a squeegee to push the front face of the bolt around while its leaking. If the leak changes tone, then it’s most likely the wrong o-ring carrier, and you have to go to the next one tighter. If it still leaks even after swapping to the smallest carrier, replace the powertube o-ring and then restart with the largest carrier.

2. Determining the number of shims needed: Now that we've got the the carrier installed with no leaks, the next step is to get the right point where the bolt will reset after a prevented chop.

Unscrew the powertube tip and drop in 2 shims, making sure they sit FLAT against each other and the top of the carrier. (If a shim gets bent, it is useless and must be replaced.) Reinstall the powertube tip and valve and air up the marker. Take a squeegee or other long solid object and place it in front of the bolt face.

Fire the marker and see if the bolt resets without having to push back against the face of the it. If it does, you are all set and ready to go to the next step. If not, drop in one additional shim and repeat. Repeat this until the bolt resets every time and there are no leaks down the barrel. If it starts leaking, remove one shim at a time until the leaks stops.

3. Using the correct powertube mainspring: The right main spring will depend on many things such as what velocity you are shooting, what barrel you are using, the size of your paint etc.

Start with the longest mainspring (silver one) from the Level 10 kit. Assemble the valve with it and gas the marker up. Try firing, if it doesn’t fire, turn up the velocity until it does. Turning up the velocity is normal for Level 10 tuning, and it does not mean anything is wrong. If the marker starts venting out the back or the velocity is too high when it does start firing, then the main spring is too long. Switch to the next shorter main spring (red one). The only reason to use the original spring (gold one) with the Level 10 bolt is to get lower velocities (usually around 250 fps for indoor use).

I'll cover X-Mags, Pnuemags and other odds and ends in this section.

A. X-Mags

When the speedball tournament scene started to really take off, the demand for light, flashy markers increased. So AGD came out with the X-Mag (also known as the "Extreme Automag" and "Extreme CNC Automag"). The entire mainbody and frame are milled out of aluminum, making it very light.

The X-Mag is essentially an E-Mag with fancy milling, but it does introduce a few features that previous Automags did not have:

1. A.C.E., or "Anti-Chop Eye": Unlike most other eyes, which tend to use two sensors in a break-beam arrangement, AGD's setup uses only one infrared reflective eye mounted vertically, aimed up through the feedneck. This provides a more reliable way to tell if a ball is fully loaded into the breach, and detects multi-colored balls much better.

The ACE board also includes an on/off switch, therefore eliminating the need for the awkward (and often lost) battery interrupt pin used on the E-Mag.

2. Changeable breach: The breach can be changed to vertical, warp left, or warp right. Changing the breach is simple: remove the barrel, swap out the breach, then reinstall the barrel to hold the breach secure. This feature allows the user to set up the marker to feed however they would like, without having to switch to a different marker.

3. Integrated rail: The rail is built into the body, making for a simpler design and ease of disassembly/reassembly.

B. Pnuemags

"Pnuemag" is a blend of "pnuematic" and "Automag". Just as the name implies, Pnuemags use pnuematic assist in the firing cycle. These marker are all mechanical.

Basically, instead of the trigger rod manually pushing against the sear to release the bolt, a pnuematic valve system is used to push the sear. This allows for a light trigger and very smooth firing cycle. Many Pnuemag users have said that it is almost as smooth as an electro marker's trigger.

Here is a typical Pnuemag setup, with the valve system mounted inside the frame:

(Thanks to FiXeL for use of this photo)

A low pressure regulator must be used in order to lower the psi of the air going into the valve system.

C. Alternative software for E-Mags and X-Mags

Several different software versions were released by AGD, but all were very limited when it came to rate of fire and firing modes in general. So, for a senior project, a young engineer decided to take on the task of developing software that would address those issues. He named it X-Mod, and made it available to download for no charge. The only fees involved were for the programmer that connected the marker's board to a computer.

The site for X-Mod is currently down, but here's the link:
www.neidtech.com

D. Warp Feed

AGD introduced one of the first force-feed loader systems: the Warp Feed. It is basically two motor-driven, flexible wheels that spin, stacking the paintballs and forcing them into the chamber. And if a jam occurs, the wheels slip over the surface of the paintballs, preventing any breaking. It has no capacity to store paintballs, so it requires the use of a hopper on top of the Warp Feed to keep it supplied. At least an agitated hopper, such as a Revvy, is recommended to keep the Warp from being starved of paintballs.

Internal view of the Warp Feed:

The most innovative thing about it is that it relocates the hopper to either the left or right side of the marker, sidecar style, thus eliminating a huge target on top. It is a bit quirky, and does take some getting used to it. But once set up properly, it can be very effective in limiting your opponent's ability to eliminate you with a gun hit.

This pic shows the significant profile difference from a regular marker and one set up with a Warp Feed:

The standard unit uses one 9 volt battery, and can feed around 10 bps. However, if you need more firepower, it can be modified to use two 9 volts and feed well over 20 bps.

The Warp Feed can be set to activate by two ways:

1.) Internal sensor: The Warp Feed comes standard with a vibration sensor, which can be adjusted for sensitivity. Most blowback markers will generate enough vibration to activate the Warp Feed when set this way.

2.) Switch-activated: The Warp Feed has a plug port which allows it to be connected to an external switch. When the switch circuit is closed, the Warp Feed activates. (Most commonly used with the Intelliframe and the switch mounted inside it.)

Warp Feed Instruction Manual (.pdf)

Pro Team Products also sells Warp Feed kits, which can be supplemented with their own products that were specifically developed for Warp Feed use on most any marker. Some of the items include a custom mounting bracket, vertical adapter, and 12 volt mod harness.

Pro Team Products - Warp Feed page