Tippmann 98 Custom Trigger Job

The trigger pull on a 98 Custom isn't one of its better aspects. It has a very heavy pull weight in its stock form and this will not aid acquiring a decent rate of fire from this mechanical semi-auto at all. Before modifying the trigger of my 98C, I really hadn't modified the marker or done anything at all for that matter to improve its performance. Out of boredom one winter, I decided to do some inexpensive modifications and a trigger job was one of them. I hadn't expected too much of an improvement but was really surprised at the difference in the pull weight and improved rate of fire that I acquired after doing so. Time well spent when you see a definite improvement as a result. I will walk you through these modifications in this article so you can rid your 98 Custom of this cumbersome, restrictive stock trigger pull.

How Can you Improve The Trigger Pull Of Your 98 Custom?

You can improve the trigger pull of your 98 Custom by performing a few simple modifications:

Install a lighter trigger spring
Rid the trigger of its side-to-side slop
Install a lighter sear spring
Minimize the full sear travel
Shorten the pre play of the trigger

Installing A Lighter Trigger Spring

The stock Tippmann 98 Custom trigger spring has thick gauge coils and makes the pull relatively heavy. You can find a lighter spring in a few of different manners to relieve the normally heavy pull:

One great resource of springs to improve your 98 Custom is to purchase a Maddman Products spring kit. It includes a trigger spring, sear spring and drive springs for your Tippmann. They can be found at local as well as a lot of online paintball stores. Simply swap the stock trigger spring for the lighter Maddman trigger spring.
Look around your house and find all of the clicky pens, mechanical pencils or any other small spring driven object or device with a similar spring and strip it of its coil(s). You will find that they will have different diameter springs in them with different tensions as well. For a Tippmann 98 Custom you're looking at something that is around 5/32" - 3/16" in diameter.
Another resource of springs is to visit your local hardware store. Any reputable hardware store such as ACO, Home Depot, Lowe's or even a ma and pa 'Joe's Corner Hardware Haven' should have an array of springs ready for purchase in different sizes and tensions. These types of springs will most likely be longer but you can simply cut them to the length you want.

Now that you have a variety of different springs, compare them to your stock Tippmann spring and put the ones that have a lighter tension to the side. Choosing the right one for you will be trial and error. You may go through a few springs before you find the one that suits you best.

As mentioned earlier, you may need to cut the spring(s). You can start by cutting them to the same size as the stock spring. If the results doesn't suit you, you can stretch them and cut it once again to a similar size as the stock spring. This will lighten the spring slightly depending on how much you stretch it and how many coils you snip. I would suggest only clipping 1/2 a loop at a time then test the results until it suits you. When installing a cut spring, keep the looped end up and the cut end down on the 98C.

Rid The Trigger Of Its Side-To-Side Slop

To rid the 98C trigger of its side-to-side slop, you'll need to slightly increase the diameter of the front roll pin that it pivots on.

This can be done by purchasing a #40 drill bit which has roughly a .128" diameter at the shank of the bit. The stock pins have approximately a .125" - .126" diameter so you're just adding a few thousandths but it's enough to make a difference. Measure and mark the drill bit then cut it with a dremel tool with an attached cutting disk or you can use a hacksaw. When cutting it, put the drill end in the vice so not to mar the piece that you're going to use. You can put the cut pin in a drill and while turning it in the drill, scrape the cut edge across a file on an angle to bevel the cut end and rid it of any rough end edges caused by the cut.

Install A Lighter Sear Spring

You can lighten the force it takes the trigger to trip the sear by replacing the stock sear spring with another.

Since they have such distinctive loops on the ends, it would be most simple to just replace it with the lighter spring provided in the Maddman spring kit.
You could modify a lighter spring yourself but if you use one that's too light, the response of the sear may not be quick enough and the sear may miss the sear catch edge on the rear bolt. This may cause your marker to sporadically double fire. Much more practical to just replace it with the one included in the Maddman kit.

Minimize The Full Sear Travel

This is kind of an iffy modification because if you perform the mod in the incorrect manner, the sear may intermittently or all together cease stopping the rear bolt from going forward after each shot which would result in sporadic or continual jack hammering.

There is a roll pin that the front end of the sear rests on. You'll need to add some diameter to this pin by making a thin jacket out of metal or plastic tubing. Some people simply wrap some tape around the pin to increase the thickness to push the front of the sear up. That is not a permanent modification though and would need to be replaced occasionally. If you make the diameter of the pin too thick, it would result in the aforementioned jack hammering. By pushing the front of the sear up, the rear portion of the sear would be lowered. This will make the sear catch the bottom ledge of the rear bolt at a lower point. This in turn will cause less travel of the sear to release the rear bolt and minimize the full sear travel. This jacket cannot be any longer than the thickness of the sear or it would prevent the body halves from going together properly.

By performing this modification, it will leave a little loose pre play travel in the trigger which brings us to the next modification:

Shorten The Pre Play Of The Trigger

If you push the front portion of the sear up, it will leave a gap between the front of the sear and the metal trigger slider at the rear of the trigger that trips the sear. This in turn will leave a bit of loose pre play in the trigger. You can either deal with it or modify the trigger and eliminate the play.

One way eliminate the play would be to drill and tap an adjustable set screw into the top of the trigger plastic between the nubbin for the spring and the pivot hole of the trigger. This would need to be adjusted and will butt up against the bottom of the valve. I would suggest either a 4-40 or 6-32 set screw. You will need to use the correct drill diameter size to correspond with the tap. A 4-40 tap requires a #43 drill bit and a 6-32 requires a #35 drill bit. If you use a bit of the incorrect diameter, the set screw can end up being too loose in the threads if using a drill size too big or the tap can be broken off or ruined if it's too small a hole. You would need to use some blue Loctite to keep the set screw in place before adjustmenting it. If you use this modification you'll sacrifice the use of the safety because if the trigger is adjusted in a permanent down position, it will prevent the safety from being pushed in.
Another way to push the trigger back would be to use a pair of 1/16" thick magnets and have them in an opposing force. You can cut a small section out of the thick plastic area just in front of the pivot hole of the trigger to house the magnets. Once the section is cut out you can epoxy one magnet to the bottom of the valve and the other to the void that you cut out of the trigger. The void would need to be deep enough to accommodate both magnets. When glueing them you must remember to install them in opposing force. If you install them in attracting force, they will push the trigger forward and defeat the purpose of installing them there in the first place. By using the opposing magnets, you will still have a functional safety because you can simply push the trigger forward and push the safety in because the trigger is not in a permanent back position.

Now that you have all of the info, there's nothing stopping you from converting that terribly heavy trigger pull to the big easy. The first time I used my 98 after modifying the trigger, I was using it to conserve on paint and ended up shooting 500 balls in that game. Didn't conserve very much paint but I was very impressed at the difference that these mods made in the ease of throwing paint from my Tippmann 98 Custom.

Technical Information