You can dl it here:
http://www.delraydepot.com/tt/sh3sdk.htm
Grab the file Mini Tweaker program.
And be sure you dl also the Tweakfiles.zip
Follow the instructions and the readme file how to operate the program.
its not easy
well when you get a hang of it, its quite easy.
Create a new folder that you can call whatever u like. Install the mini tweaker program in that folder.
then unzip the tweakfiles to same folder.
Start the program.
Up in the right corner of the program there is a small button called:
Locate alternativ game folder.
Find where you have installed your game like: D:/Games/sh3 and click ok then. Be sure you are in the root folder of sh3.
Then click: Load tweak file.If you are not directed directly to the folder where you installed the tweakfiles then you just click you way to where you installed the mini tweaker program. This is important coz you are gona use thos tweakfiles you unzipped to that folder.
Then find the file called Guns Sub Sim.txt and click on it.
You will now get a bunch of values in the window. from the small list window above you can choose the gun you prefer to change. Find the value
Reload_time=xxx
click once on that row. then you get a marker in the right window where it says new value. Type in what you want and click on the button,, save new value,
And there you go.´
As soon you do some changes to a file it will creat a backup file of the original file.
You can find that file in sh3/data/library folder later if you want to rollback.
Or write down the values before you do some changes on a paper so you remember the default values if you want to change back.
Hope you understod this explaination or if you have more questions about it,, just do a post
good luck