I'm would caveat the safety by staying under 400fps w/0.20's....
It really does depend on who you're playing with. For some games we end up playing at, "keep it somewhere under 500fps"...for the odd one it's, "meh, whatever you're using". For many of the more memorable ones it was a 450 cap. All of those have been with known shooters...everyone knows everyone else well...there's lots of maturity, respect and discipline going on.
For general public games...400 is fine. And for indoors...350fps is (IMO) too stiff...I'd rather see 290-300 with ZERO min engagement ranges. 400 in a tight environment is just plain painful.