The "4" that you see appear in the updated code first shows up in WL_AGENT.CPP ... almost at the very top. You should see an array of numbers for the weapons, and it looks something like this:
::: CODE :::
} attackinfo[4][14] =
{
{ {6,0,1},{6,2,2},{6,0,3},{6,-1,4} },
{ {6,0,1},{6,1,2},{6,0,3},{6,-1,4} },
{ {6,0,1},{6,1,2},{6,3,3},{6,-1,4} },
{ {6,0,1},{6,1,2},{6,4,3},{6,-1,4} },
{ {6,0,1},{6,1,2},{6,5,3},{6,-1,4} },
};
Note how each set of numbers is grouped together into three numbers. The "4" in question is the middle number. Whenever that number is called up, that's when the "jamming" code is called up.