The 10G figure is one I found on a site describing Aresti maneuvers for full-size aircraft. It may even have to do with the outward pull from the centripital forces on the wings(?)

http://www.bruceair.com/Aerobatic_Intro.htm

Here's the definitive FAA report on g-force effects to the human body and what maneuvers cause how many.

http://www.faa.gov/library/reports/m...ia/AM72-28.pdf

The FAA report lists 3 G's for a 2.9 second snap roll. In a model the snap roll takes less than a second, but I haven't found my "10G" source yet so I can't confirm that.

Interesting to note that a loop itself is a 1G maneuver. Entering and exiting the loop are where the G's are experienced.