Do you have to reload a speed loader? I genuinely have no idea how they work.
For example, let's say there was a ban on civilian purchase of weapons with magazines (so no current guns get taken away). Instead, civilians would have to buy revolvers, rifles that get loaded one bullet at time, etc.
1) Do you think that would significantly impact the ability of a householder to defend themselves against an intruder?
2) Do you think that would significantly impact the ability of a mass shooter to kill a large number of people?
Here's a speed loader

You push this into the cylinder of a revolver and twist the knob on the back to release the bullets. You can get a holster that can hold several of these. The police often use them.
https://www.youtube.com/watch?v=BOgu4yJAWoI
1) No, I think few situations require several rounds be fired. I'd say it's much more of a "It's better to have it and not need it than to need it and not have it" type situation.
2) No detachable magazines at all? Yeah, it might limit the fewer than 100 people a year who are killed in mass shooting to fewer than 99 per year. So would a universal 25mph speed limit with vehicles equipped with devices that limit their speed. But we're not seriously concerned about life if it means our commute would be longer.