VibeSurfer,
Is it possible the different effects you had were due to different potency of cact? Because ime psychedelic effects are clearly dose-dependant in a very predictable manner with mescaline too (taking in account variables such as mode of ingestion, tolerance, set/setting, etc). What varies the most is genetics of cact.
Also, you mean 520
mg, not g, right?
OneIsEros,
Check
this thread for relevant info
Normally people recommend taking around 300mg of mesc for first experience.
You might be naturally tolerant/resistant to some psychedelics, but not to others, since pharmacology can be different.. If you want to play it safe, you can stay at that dose. On the other hand, IME generally mescaline is very forgiving and much less likely to precipitate a negative experience (though obviously set and setting recommendations still apply), so it's not necessarily a bad idea to consume some more. A higher but still manageable dose (for some people) of mescaline is maybe 500mg.
Let's take a 0.75% dry average mesc content (near the bridgesii and pachanoi averages as calculated in that thread), that's like 67g dried cact to get 500mg mesc.
Mind you, that's talking averages, you may have a way more potent or a way less potent cactus, genetics matter a lot. You can always adjust and take more or less some other day, depending on how the first experience goes and when you find the potency of your cact.
You can try eating cact powder, i've done that before, but def not pleasant. Hard to swallow, hard on the stomach, but it works! You can try some kind of extraction on it. I'm not sure how soluble mesc in it's natural form is in alcohol, I'd love to know. I've mostly worked with fresh cact so I brewed small pieces of it and filtered, with powder you'd probably have to work around the snot issues (there are some tricks to deal with it apparently) when rehydrating it. Or you can try a proper extraction and crystallizing it in some salt form, my choice is with fumaric acid.