I made a big mistake today while testing a 78, won't tell you what I did as someone else will try it and get hurt. Got in a big hurry and forgot to do something, chronied at 1175. Filled my shorts I'll tell you and won't forget again. When it happened it blew all the o-rings and probe seal, lucky for me I had my glasses on as they had bits of rubber all over them. I think this may be a record velocity for a 78 while using only one CO2 cylinder.