RT Pro/carbine
Warning/Disclaimer: This modification requires some precise measurements and careful drilling.  If done improperly, new parts will be required.  This is also a very young modification and possible bad future effects have not become apparent.  Also, I am human and may have made a typo.  It is best to understand the idea and make your own measurements.  Doing so will also take care of any possible differences that Tippmann made between individual guns, whether planned or machining imperfections.  I tried to mirror the Model 98 in terms of pull length of the trigger and placement of the ram cylinder.  Even doing this mod correctly does not ensure success.  As I have found by doing the second installation, some valves may not allow the kit to work correctly for what ever reason.  While trouble shooting, I found that when I put my valve in his gun it worked just fine.  It may be the spring so if yours doesn't work and you feel you followed the directions properly, call Tippmann and get either a new valve to try or a valve rebuild kit which I believe contains a new valve spring. 

Tools needed
Calipers (a good drafting ruler can be used instead)
Carving knife gouge-(A chisel with a rounded, trough-like blade.)
Drill press
10-32 tap and 5/32 inch drill bit (can be bought as a pair)
Center punch and light hammer
¼ inch drill bit
Rotary tool (Dremel) with cut off wheels and grinders.  May also need cutting bits. 
Router table(optional)
File, belt sander/grinder, or bench top wheel grinder

Procedure:
1.Remove all paint and air sources from the gun. 

2. Note: This step may not be required.  I did it to mimic the 98 as close as possible.  Next is shortening the trigger pull distance, another critical step.  Grind the ledge to   1/16 inch from surface E, and be sure to keep the ledge square (remove equal            amounts of metal from both ends of ledge).  When grinding, take it slow and have a    dish of water near to cool part in.  If the hammer gets to hot for you to comfortably      touch, you can change the temper/hardness of the hammer and cause the part to       wear more quickly. 

3.If you did the above step, you will need a way of stopping the trigger from over travel to increase the performance of the rt modification and still have a safety.  The stock   specs allow for movement of the trigger and sear while on safe, just not enough to      fire the gun.  The above modification causes this to become un-true.  I fixed this problem by adding to the safety engaging part of the trigger as seen marked H.  I used epoxy on mine, but stainless steel held with epoxy on the second one I've          done.  You will have to make a decision on how to do this yourself.  The wider part of the safety(G) is now the over travel stop.  I can not give dimensions since each one will be slightly different, depending on how much sear ledge is left.  You'll just have to test fit it until the gun fires. 
              
4.Open up the grip frame and take everything out, including the pins.  Also remove the valve and power tube from the gun body.  Measure 1 and 35/64 inches from the top edge of the grip frame down perpendicularly, marking towards the front and back (most importantly the same distance) then drawl the line between them (A).  That is the line of deepest material removal and where the ram will hit the trigger.  Do this to both halves.  You may find it easiest to trace around the cylinder of the ram, cut the trace out, and use it as a template to determine where material needs to be removed.  If you can use a router table with the appropriate bit it may be easier and quicker.  Take out only what needs to be removed for complete closure of the halves.  Also mill room for the hose and fitting.

5.The kit can be installed on either side.  From the back of the body measure 4          and18/64 inches, marked (F).  One of the most critical measurements and it is better  to be a little over than too short.  Punch the mark with the center punch to keep the   drill bit from wondering off the drill mark.  Drill the hole with the 5/32 bit.  After drilled,  tap the hole with the 10-32 tap.  Use kerosene or other light oil to lubricate when       taping the hole.  Clean body well with a degreaser inside and out, such as soapy dish detergent or alcohol.

6.Attach the appropriate side of the grip frame to the body and screw the air transfer   hose into the newly tapped hole in the body.  Mark the center of where the                 adjustment screw fitting reaches for drilling with the ¼ inch bit for the internal             elbow.  By my measurements it is 37/64 inches from the top edge, and 1 and 1/8       inches from the back to center of this hole. 

7.Now, make a flat spot on the trigger for the ram to push against(B).  You will           probably have to cut the ram piston shorter, as I did.  With the grip frame                   reassembled and on the gun, measure how far the trigger must move before the          hammer is released.  You can do this by placing a ruler under the frame and slowly    move the trigger back until the hammer is released.  Remember the distance and       now take one half of the grip frame off (which ever doesn't contain rt adjuster).            Move the trigger the distance you measured for hammer release and mark a line         perpendicular to the ram on the trigger, then remove all metal behind that mark in       the required area.  Also mark the ram shaft and cut it where appropriate.  Keep          both of these parts cool while cutting.  I put an ice cube against them. 

8.The final step is not required, but it is recommended.  Since you have put the ram    were the trigger spring pin was, you must find another way to spring it.  I followed       the 98 custom set up and put the spring in front of the trigger, as seen by C and D.     An extension to push on the spring and a hole for the spring to be placed in at the      base of the trigger guard.   The extension must be narrow enough to fit in the slot      in the bottom of the body. 

One last statement:  When epoxying an add-on to the trigger, be sure the surfaces are rough and clean.  Otherwise, it will fall off much easier.  If you have the means, brazing may be better.  However, the heat required in the brazing process may soften the trigger steel..That is why I just "glued" it.
If you do not have the means to do this mod but still want rt, contact me and we'll discuss what can be done. 
If you try this let me know how it turns out for you.
Eric, first out
March 26, 2003
For those of you who have been asking for it, here it is.  If you need anything clairified, E-mail me.