Interesting Sound Measurements

[WhatUPSbox?]

I was shooting wadcutters into shipping foam. It was very quiet but each shot cored out a clean foam worm. Your stacked foam is different but pointed or domed pellets may be better. I'll try those next time.

[jsk68]

This foam has a consistency more like a plastic card board it's fairly rigid, it was actually just an experiment, so far so good. I shoot a lot indoors and the clank of a metal trap just isn't an option.

[WhatUPSbox?]

For completeness, I added the front cover plate (from post 41) to the sound box. It is plywood with thin foam on the inside and a 3 " entrance hole.
I repeated the tests with the CP1 and the soundmeter in front, facing the target. The results for the box with the front cover were about 13 db lower than either the plain paper box target or the open box without the cover.
I have some ideas to make the cover more practical, but that combination got me to below 75 db in each of the directions for my test configuration.