Dud Tpx

So I win a Tpx at Tipmann challenge (sweet). Air it up fire two balls try to chrono it. it's low but screw doesn't seem to move much next ball chops. Try to shoot it clean no good. Put gun away to clean latter. Get home clean gun up shoot it in the garage discover one of the 7 round mags does not feed properly and causes more breaks. Clean gun again try to fix mag. No real burs or bad spots for the spring to catch on so put it back together grease the spring and still no good caches after 3 balls. Ok can live with that get new mags. Try gun again with other mag seems to work great. Next time I go a field try to chroney it again and screw is very tight in both directions. Un air it try screw seems ok air it up shoot it gun sounds like it's internals are eating them selves. Take it home for the winter. Take it apart last week everything looks ok grease it fires great. Take it to a field to chroney fires 235 turn it up screw works (yes) fires starts leaking down barrel. I'm an old mag guy figure out that when the trigger is held down no leak released leak. Manual says to clean or replace Z o rings from diagram on page 18.I have to use snap ring pliers to get to these. Questions is this something I should do my self or should I throw this piece of crap at the next tipmann teck I see. Have maybe fired 50 ball through it think that is high why would these be leaking that soon. Sorry for the long post is mostly a frustrated rant but do need the question answered thanks.