Everyone reacts differently to morphine and oxycodone, this topic has been covered hundreds of times please use the search engine if you want to read other people's opinions about them, we don't allow drug comparison threads like these because it's not about harm reduction. The pertinent HR value and the only one I see here is that most people tend to associate morphine with intravenous use because of it's low oral and intranasal bioavailabilities that's why most people abusing them take them via IV and it's super dangerous because people underestimate the power of morphine. But most people I know don't like the extreme potentially adverse effects such as the extreme irritation/histamine reactions at the IV site. They also forget that when IV'd, it's much more potent than oxycodone, like 2-3x stronger.
Oxycodone on the other hand, shouldn't be injected for any reason at all ever because it is very well absorbed via the oral route of administration. Intravenous abuse of oxycodone has no benefits over the oral route and if you're going to continue abusing these drugs at the very least learn how to do so safely.
