same thing i heard... if a 3k tank then multiply the ci by 10 and 15 if its a 4.5k tank
so for a 68ci/3k tank, figure ~700
for 68/4.5k ~1020
on my 88ci/3k tank, i put about ~1000 shots through my gun... I am using the LP kit so that may help with efficiency...
It's not what you shoot, it's what you hit.