Originally Posted by Tench
There are lots of variables that rule out a general trend, reg volume, reg pressure, port dia, valve duration, barrel length etc that can make a gun produce more power with a pellet of different weight to the one it has been set with. I have witness both lighter and heavier pellets doing this under different circumstances so we cannot presume unless we have tested with a variety of pellets that our rifles set under with what we are using wont be over with something else.
And the closer you run it the greater the risk.
Good points Tench, I don't think there's a massive problem, well if there is we certainly haven't heard of it.