Rhone Man,
I have blown out the o-ring in my SR1 and so has my mother. Can you share the trick you refer to?
Girlsgonediving
Sorry, just noticed this post. The key is to stop the first stage piston pushing out too fast. There are two tricks - I always try to do both. First is just to press your thumb down on the first stage piston from above (ie. the black rubbery cap) to prevent it shooting up too fast when you turn your gas on. The second is that when you turn your gas on, try to depress either the power inflator or the purge, so that some of the pressure is diverted away from the piston. Might be overkill doing both, but I haven't suffered a blowout since my LDS suggested that I try that.