well being it's the tip 90's and I have no idea the mixes you are pumping nor the quality of 90s you purchased but those 90s take a beating and if they're just standard single wall 90s pretty sure that's about all you are going to get , if you want more look into the double wall or impact 90s

are they duel wall?

no single skin two early to wear out this quick

that's all I get out of single wall tip 90s is about 5-6k yards , dual wall I get a little more

if the pipes are not full as much as possible, id have to agree with you pudg2