I was able to shoot oxymorphone once and it was pretty sweet. I have no trouble to sticking to insuffulating it though, and have never IV'd anything else, and only did it that ONE time. As far as oxycodone, i don't know, even shooting once you are taking a risk, and i don't think that OC is worth that risk. If you really want to experience an IV opiate try to shoot for (hehe) heroin, hydromorphone, or oxymorphone. That way you'll never wonder what a better rush might be like.
And like I said, I was able to do 10mg of oxymorphone (the champagne of dope) and yeah, it felt good but it's not like my life is destroyed by dope or anything now.
Just be safe when you do it (extremely sterile, etc...)