It is strongly recommended that you make some sort of testing box, when conducting testing. Below are pictures of one box made and used by Lord Julien de LaPointe, to measure penetration of a blunt and the impact of that blunt. Here is what Lord Julien said about his testing box:

"For the second round of testing I constructed a wooden box with a steel rod bar grill across the front and put plastersine clay inside. The rods were ¼ inch in diameter and spaced from 7/8 inch to 15/16 inch apart. The clay was leveled out so that it was approximately 5/16 inch under the grill.

**we recommend using this: Foliage Fresh Wet Foam, which is a 'walmart brand' item (ie, has the 'made for WalMart' stamp on the label). The person who made this test box (below) found the plastic clay difficult to smooth out to the required level inside the box.  

The next test I conducted was to remove the grill from the box and to fire a shot directly into the clay to determine how much impact was actually occuring."

I have a couple of suggestions. First make your bars the exact same distance apart, that makes it easier, so we don't have to measure the spacing after the shot. There is a green floral foam, Foliage Fresh Wet Foam, which is a 'walmart brand' item (ie, has the 'made for WalMart' stamp on the label) that works great. If it's possible, it might be worthwhile to make your testing box so you can change the grill or plate. That way you can test different spacing and flat metal (something to imitate the ocular style helms). If you are limited to one choice, make you spacing 1" exactally, since that will be slightly worse than worse case scenerio (our margin of error).

We are still trying different materials and different testing boxes. If you have created a testing box or something different to test for penetrations, please let me know. I would love to hear of other options, suggestions and short cuts (even tips on what not to do). The more we work together, the better.

I would like to thank everyone for their help, especially Lord Julien for making and taking pictures of his test box. Thank you for giving me permission to share your pictures and directions. I also want to thank THL Siegfried for finding the best (at Walmart, grin) green floral foam.