The Apollo lunar missions experienced max G forces of 6.5-7.2g during reentry. (The Earth orbital missions only went to about 3.3g.) See: http://history.nasa.gov/SP-368/s2ch5.htm
Alan Shepard freaking flew Mercury 3 by hand during a 11.6g reentry.
Ejections seats are 12-14g or worse.
Of course, max G is only part of the equation; duration is the other. You can handle really high forces if they aren't for long. Given the short duration and lack of need to keep the occupants awake they could go a lot harder. I'm actually a little surprised it's so gentle.
The Apollo lunar missions experienced max G forces of 6.5-7.2g during reentry. (The Earth orbital missions only went to about 3.3g.) See: http://history.nasa.gov/SP-368/s2ch5.htm
Alan Shepard freaking flew Mercury 3 by hand during a 11.6g reentry.
Ejections seats are 12-14g or worse.
Of course, max G is only part of the equation; duration is the other. You can handle really high forces if they aren't for long. Given the short duration and lack of need to keep the occupants awake they could go a lot harder. I'm actually a little surprised it's so gentle.