I agree there's plenty of addicts who are idiots, and don't have a clue how their drugs work or how to use them semi-safely.

But it only takes using morphine once to realise it's bad. Usually you buy it for oral use, and it's bioavailability is laughable when taken this way. I think even the dumb addicts would avoid it. Even the dumbest of the dumb know how it feels, even if they don't know how it works. Even IV morphine is more expensive and weaker, so it feels worse, and costs more, even with the more efficient ROA.

Truthfully speedballs with morphine would only be done by people scared of heroin, before they switched to heroin. Addicts would use heroin.

I will say, however, that this will be changing. Becasuse of Nitrazines and fentanyl in heroin, people may start switching to morphine because they believe that it's safer (and honestly they're right). The USA has had a fentanyl problem for a while, but the afghan crackdown on heroin is causing the rest of the world to switch to other opiates like nitrazines. Although most samples in the UK don't contain it, it's not effectively monitored and it seems to be on the rise. This could mean that, in the future, speedballs contain morphine more and more. But like I said, it doesn't make sense to mix with heroin specifically. It will either be heroin or morphine, unless the morphine is just conveniently there.