Hello Leland!

I will never join you on the Paintball Battlefield but I still find your project very interesting.
The original electronic of the DM4 Paintball gun is based on the PIC16F628A. My advice is to do first some reverse engineering of your DM4 in order to figure out its electronic circuit. If you don't understand the electronic circuit of the DM4 there is a risk that you will cause some damage while experimenting on it. Make sure there is no danger for people during this project and that your soldering iron it is in a safe place all the time. I hope I will never hear on the news that a Paintball shooter has been arrested in Leland South Carolina.
Also if you work on your DM4 you will probably void its warranty. Once you have the schematic on paper, replicate the circuit with all its components on a breadboard and start your programming from there. Start with a simple program easy to verify on your circuit on the breadboard. (Simple program = Just one shot). When you are confident your program works on the breadboard, then replace the original PIC of your DM4 with the PIC you have programmed on the breadboard. Try your first simple program on the DM4. Go back with your PIC on the breadboard and work more on your program. I am sure it is going to take several months before you will achieve what you are looking for. During this time people on this forum will help you discover the features of the PIC16F628A and overcome the difficulties you will for sure encounter during this project. This is my personal opinion but if you have questions for people on this forum try to limit the scope down to the particular feature of the PIC you are implementing in your program in that particular moment. Try first the feature aside your program. A small program is simple to understand and share for discussion on a forum. Also most of these questions have already been answered on this forum. Use the search tool of the forum. Open also the Datasheet of the 16F628A and all related application notes. (Microchip web site).

For the readers of this forum there is link to a web page that will give some ideas of a similar project.

http://www.wickedairsportz.com/products/eqdm4.htm

Have fun!


Regards

Luciano
(Beretta 9 mm).