Question on buccaneer and golden veins

Is there a cap for damage/hp multiplier for buccaneer and golden veins on gold find ?
When I had gear with 4 gold find crystal affix total i do around ~12-15m damage for scatter shot
when i wear 1 more piece of armour with gold find crystal affix i still do ~12-15m damage only
I also found that my hp doesnt go up when i wear the 5th piece of crystal gold find affix too

in short: damage and hp stay the same when i am wearing gear tht have 4 and 5 crystal gold find affix