Your process for trying to get high from Bupe was your problem. Bupe is not a drug that there is ANY POINT in redosing because it lasts so fucking long. Odds are, if you're opiate dependent/experienced at all, the second dose you take is NOT going to get you any higher, just prolong the experience. Tolerance with super potent Opiates like Bupe work way different than less potent Opiates. It was good that you did this as a test experiment so you know how much you can handle tho - although you need to make sure you know the how well each ROA absorbs the Bupe. Oral, you only get 10% of the dose, Sublingual you get 30% of your dose, Sniffing you get 60%, IV is 100%. If you're trying to get HIGH off Bupe, don't waste your time eating it - all it will do is fuck up your tolerance and make it take longer for you to be able to achieve a decent high again. Decide the dose you want to take, from what you've taken previously - I would say sniff between 4-8mgs all at once after at least 36 hours of not taking any Bupe. If you do this, I guarantee you will see a different side of this drug. When you're actually able to get high from Subs, which is honestly a pain in the ass and a bit of an art to get good at - the high reminds me of Heroin more than anything else. Good mood, stoney feeling in your head, relaxed throughout your body, slight nodding off, super lazy high usually. It's actually quite nice if you do it just right and get to the sweet spot of the drug. It's not meant to get you high tho - that's why how you were taking it was NOT working. They are best kept for a rainy day when you can't find anything else, to keep WD's at bay, or just take them as prescribed so you don't have to be an addict.
As for how long you should wait before you try that Oxy or whatever it is you want to take - I would wait NO LESS than 3-4 days at a minimum. Bupe hangs around for a LONG TIME when you aren't used to heavy Opiates, and anything above 4mgs will block the effects of any other Opiate COMPLETELY. EVEN IV HEROIN, so you're little 40mg pill ain't breaking thru shit. My recommendation, hold onto your Oxy for at least 4 days, and then sniff the whole pill at once. It still probably won't do much for you. Oxy is fucking weak and lame in my book. Find a better Opiate if you want to party. 1g of Codeine is no joke - it can still lead to addiction and chasing the dragon one day............Be aware. Oh yeah, if you have some Bupe left, give it another try in about a week and do it like I said. No Opiates the day prior to taking it so there's no Precipitated WD's (LOOK THIS UP IF YOU DON'T KNOW WHAT THIS MEANS!!) - and then take your dose nasally all at once. DO NOT TAKE MORE THAN 8mgs nasally your first time. That's a pretty hefty dose. Bupe also has a Ceiling Dose of 32mgs - anything even CLOSE to that is fucking pointless. Bupe can be fun and a useful tool - you just have to know how to use it to your advantage and get the most out of it.