The military rifle is by far the most complex wooden gun among the 9 gun designs in this set of plans. I decided to build the simpler hunting rifle and western revolver first, before tackling this complex project. I always enter project plans in Sketchup because it helps me learn the design and often plans have errors.
The plans call for a whistle built into one of the 2 dowels in the left hand gun section. No details for making the whistle are in the plans.
From past projects, I have learned that building wood whistles is a trial & error process to get a good sound.
I set up an Excel spreadsheet to run experiments and home in on the best design.
I made the reeds about 1/2" longer than needed, so I could grip the end with my fingers and change the insertion length. When I am done, I will saw the extra off flush with the end.
It took 3 attempts to get a good design. My first attempt failed, so I drilled the hole deeper to give the whistle more volume. I tried a thinner reed and that did not work well. The best result was with a thicker reed [which means a narrower air passage], and it was less sensitive to the insertion length of the reed.
Out of curiousity, I went ahead and tried a 45 degree angle cut. WOW, it gave the best results so far !