Owner's manual

When it comes to your airgun "IT'S NO GAME!"

You have purchased the best available performance
upgrade you can by for your VM68.
AIRGUN DYNAMICS only makes performance enhancing products.
If it doesn't improve performance we won't make them!

11353 Pyrites Way #7
Gold River, CA. 95670
PH. (916) 851-1870
FAX (916) 851-1870
Website: www.airgundynamics.com

Pro-Comp v.3
Installation Instructions
For ultimate performance and reliability instructions must be followed precisely.

The Pro Comp v.3 has been designed to be installed with a few simple tools.
These are the tools and supplies you will need:
3/16 in. Hex wrench
5/32 in. Hex wrench
1/8 in. Hex wrench
1/4 drill bit and electric drill
Valve removal tool
Sand paper (supplied)
Pneumatic oil (supplied)
Read instructions thoroughly before you begin.
If you have any questions contact AirGun Dynamics.
If your not sure about installing this kit check with your air smith.

Installation instructions


1) Completely field strip your VM68 by removing your upper and lower bolts, main spring, rear plugs, valve assembly, trigger housing. (Do not disassemble trigger assembly.)

2) Wash your receiver and trigger assembly in hot soapy water, liquid dishwashing soap, and a bottle brush works good for this. Completely dry parts with compressed air. If a compressed air is unavailable you can use a hair dryer and paper towels.

3) The top edge of the primary and secondary trigger sear must be sanded smooth so it won't cut into the Delrin hammer guide, this is vital to the life of the guide. This step must be done correctly. (Note that a coarse and fine grit sandpaper have been supplied with your kit.) Use your finger and the coarse sandpaper first and sand the sharp edge off the tip of the primary sear, do not sand to much, just enough to make it smooth. On the secondary sear sand the corner smooth as shown in figure 1. Once you are satisfied that they are sanded properly use the fine sandpaper to polish both sears. Test the sears by holding the PRO-COMP hammer guide on top of the sear parallel with slide smoothly without shaving the Delrin guide. See figure 2. Make sure absolutely no Delrin is being shaved off this is VERY IMPORTANT!

4) With the receiver disassembled and cleaned, use your 1/4 inch drill bit and drill through the existing 3/16 inch holes as shown in figure 1. Test fit the quick strip pin, it should be a snug fit.

5) Now you must deburr the rear of the receiver. Feel inside the rear of the receiver for any sharp or rough burrs that might scratch the new parts when you install them. This is IMPORTANT! If you feel any burrs you must smooth them out by scraping them with a pocket knife and sandpaper. Make sure you check the upper bolt hole also.

6) Once the trigger sear is sanded properly and the receiver is deburred its time to wash the trigger and receiver again to remover all the shavings. Any shavings or sanding grit will cause unnecessary excessive wear on your PRO-COMP parts.

7) With everything clean and dry, slide the PRO-COMP cocking knob and upper bolts system it into the receiver, it should slide in smoothly without binding, if it does bind check for burrs. With the system in place the upper bolt should slide back and forth freely, if it doesn¼t check for burrs. Once the system fits properly you can remove it for now.

8) Now it¼s time to reinstall the valve using the new valve spring that came in your kit. This is a good time to inspect the cup seal and valve housing O-rings, replace them if they are worn. Install the valve, set it in the 12 o¼clock position (largest hole setting). Install the two supplied nylon gaskets on the valve retaining screws, (they are a tight fit and need to be threaded on to the screw) and just snug them down, don¼t over tighten them. These will eliminate wasted blow back pressure that escapes through the screw holes.

9) Put a drop of oil that came in your kit on each of the pivot points on the trigger mechanism and reinstall trigger assembly and grip receiver.

10) Lets install the PRO-COMP side covers now. First make sure that the sides of the gun are absolutely clean and free of oil residue. Wipe them thoroughly with rubbing alcohol. Make sure the receiver is above 68 degrees F, you can warm it with a hair dryer. Measure in from the rear of gun 1-1/8 inch and put a pencil mark, peal the backing off the back of the side cover and align it tipping the top edge into the groove that runs along the gun and laying it down, press it firmly in place. It takes 24hrs for the epoxy tape to cure completely.

11) Now you can install the upper bolt and hammer system. Lightly coat upper bolt, hammer and hammer O-ring with the supplied oil. Slip upper bolt on to hammer link pin, IMPORTANT! ALWAYS DEPRESS TRIGGER BEFORE SLIDING UPPER BOLT AND HAMMER IN OR OUT OF RECEIVER! As you slide system in, with trigger depressed, the detent button on the spring guide must face the flat on the cocking knob, slide the system all the way in, you will have to push the spring guide in and push quick strip pin into place. This may seem a little awkward at first but with a little practice you will have it down. Now you can grip cocking knob and pull out to cock gun, push knob in, it will click into place, to decock gun pull knob out, while holding knob out depress trigger and let knob down slowly. Dry firing is not recommended it can cause unnecessary wear and possible damage.

12) Now the fun part! Install feed adaptor, barrel and barrel plug, YOUR BARREL PLUG IS YOUR SAFETY, ALWAYS USE IT! Cock gun, push knob in and install you air supply. Go ahead and fire about five shots, remove upper bolt and hammer, inspect hammer and guide (Delrin part of hammer) to see if trigger sear is scraping the guide if it is sand it a little more, there should be no scraping at all. Double check it after about another 50 shots. You now have a super high performance VM68 that is known as a PRO-COMPv.3 and it¼s ready to rock!

13) ALWAYS chronograph your airgun before you play! See tuning your PRO-COMP in this manual for tips on setting your velocity.


Tuning your velocity

Setting you velocity is simple, fire a few clearing shots then shoot you PRO-COMPv.3 over the chrono. If the velocity is to low slip a 3/16 hex wrench into the end of the cocking knob and engage it into the adjusting screw and turn it counter clockwise (note: some times the adjuster will be hard to turn if it has not been turned for some time, if you encounter this always turn the adjuster clockwise to free it up then counter clockwise.) If the velocity is to high turn adjuster clockwise to slow it down. Check the tuning of your velocity by removing the upper bolt after you get the velocity set where you want it and see how far open the air hole is open in the upper bolt. If it is almost completely closed the gun is over tuned and you should try turning the valve to the next smaller hole or try a stiffer valve spring, you will have to experiment with it to get the best performance and efficiency.

Lubrication and maintenance

Always use a high quality light weight pneumatic oil, never use grease, heavy oil of oils with solvents in them. The proper oil is vital to good performance!

There are two ways lube your gun. The first way is to add a few drops of oil into the ASA adaptor before airing up (always cock gun before airing up) and shoot your gun about ten times, remove barrel before shooting to avoid depositing oil in it. This works good if you haven¼t cleaned your gun from the time you played. The second is to field strip the gun and wipe off old oil then put a thin coat on all moving parts and hammer O-ring. Field stripping and washing receiver and parts with warm soapy water, drying and lubricating is recommended periodically.

Proper maintenance will give your PRO-COMPv.3 a long trouble free life.

Please see our website www.airgundynamics.com for the latest technical updates and E-mail us with any questions of suggestions. Thank You!