The most informative test I can imagine is a series of high speed photography shots of the various gauges being shot with adapters. A 12 gauge barrel , 16, 20, 28 and 410 chamber adapters, and a supply of shells should be all that is needed to photograph the exit shot stringsand answer this question. If anyone knows on of the people who post these types of tests on the internet, they should contact them and propose a series of tests.