Hold on a second.....Is the OP thinking of filling caps without even measuring the molly first? Are you
kidding me???
Never,
ever fill caps without measuring how much molly you are putting in them. What do you consider to be a standard dose, 100mg? Do you know how small that amount is in pure, powder molly?
For my sake, OP, please, before you buy your caps,
buy a scale. You are risking your health by guessing dosages based on cap sizes. Unless you are extremely experienced in filling caps with any substance similar to molly, you are not qualified to fill a cap before measuring the dose on a scale. At the very least, you risk wasting a lot of money trying to get the dose right, because you'll likely end up vastly overfilling the caps the first few times. And if you try to play it safer by getting small caps, it's extremely hard to fill them without getting the contents everywhere. The small caps are nearly impossible to use without the help fo a filling machine.
Even if you decide to parachute instead, as was suggested above (which isn't a bad idea, assuming you're making these pills just for yourself), measure your molly first.
Be safe, I don't want you getting hurt because you didn't measure first.