ShimCalc is a simple python script that determines the best possible combinations of shims to time a muzzle device.

Python 3.X

The required inputs (found in inputs.py) are:

• shims - A list of available shims to stack up;

• threads_per_inch - Threads per inch of the barrel/muzzle device thread;

• degrees - How many degrees of additional counter-clockwise rotation are needed to get the muzzle device timed, based on where the muzzle device times without any shims.

• orientations - Number of possible install orientations (1 = only one way to time, 2 = no defined "top" or "bottom");

• max_height - Maximum height for the stack of shims.

Running ShimCalc.py will print a list in the console/terminal with the following values:

• Angle - Nominal/target degrees of rotation for the muzzle device from the starting point (can be ignored);

• Shims - A list of shims to use for that possible install option;

• Error - Estimation of how far off in degrees the install option will be from the nominal target.

  Angle: 30.0
  
  Shims: 0.003
  
  Error: -0.24º
  
  
  
  Angle: 390.0
  
  Shims: 0.002 + 0.003 + 0.004 + 0.03
  
  Error: -3.12º
  
  
  
  Angle: 750.0
  
  Shims: 0.002 + 0.002 + 0.003 + 0.003 + 0.004 + 0.004 + 0.008 + 0.008 + 0.01 + 0.03
  
  Error: 4.08º
  

This calculator does not take into account deformation of the shims from compressive forces, on the assumption that the amount of torque generally used for installation will not cause significant deformation. That, and the code would get super complexificated.