those "pistons" are actually pistols, they are hairs the female makes that catch floating pollen.
pistols have little to do with maturity, for maturity you use a 30-60x magnifier and look at the trichomes.
trichomes get filled with our favorite chemicals and help you find out when the plant is ready to harvest
many first time growers think pistols are trichomes, research and know the difference
patience is key to getting a harvest worth smoking, don't cut it too early or you'll be skimped on what could have been
keep everything green, don't give them bloom boosters when the bottom leaves are dying from lack of nitrogen. Make sure they eat a well balanced meal is what i'm saying