SpudFiles

right now i built my first gun.. it has a 4ft 3" chamber, and a 5ft 2" barrel, and a 1" one... with the 1" it shoots rocks baout 200yards at about 90psi.. i know the valve is slow to open, and i tried my 2" barrell n put a golf ball in it.. it barely even made it out of the barrell, 2 feet maybe.. i don't really know why... but i am asking if i do the mod sprinkler valve.. i know its faster.. but what kinda perfomance increase will i see? with the 1" barrel will it go from 200yard to 300? and the golf ball situation?

The performance will at least triple.
You should invest is sdr-21 golfball barrel.

how many psi was it at?

the golf ball? 70,, i've had it up 160 PSI on the 1" barrell

The GB aint going anywhere as there is too much blow by as the golf ball doesnt fit well enough in a 2" barrel, either wad the golf ball or buy 1.5" SDR-21