Upon entering the Muzzle Exit analysis module, the user will see the Muzzle Exit form's setup page as shown below. Note that the left frame, Analysis Setup, contains inputs and the right frame, Calculated Values, contains outputs.

Let's look at the inputs for this example. The bore diameter, muzzle velocity, twist and exit spin ratio are all passed through from the Stability module, via data retrieved from Gun Reference books or entered by hand. The user enters a value for the bourrelet diameter either from a tolerance study (for medium and large caliber systems), or experience, in the case of small caliber systems. Here, the 29.972mm bourrelet diameter is the reference diameter passed through from the Mass Properties module. In any case, the bourrelet diameter should be somewhat smaller than the Gun Barrel Bore diameter, not larger.

In our example the only input that we will change is the bourrelet length. The next slide will go over how to determine the bourrelet length.