That's what happened to the Colorado shooter. Drum mag and weapon jammed, then he switched to a Remington 870 and really did some damage.
Got my QuickStrips. The 357 strips; The design allows for ease of carrying in a pocket or two, or a QS pouch on your belt. Hardly any more room than a mag. I've not used a speed loader so don't know which is faster, probably the speed loader, but the ease of carry requires a special pouch and they'd be bulky in your pocket.
The 12g QS allows for ease of carry in a pouch or Bail Out bag in a qty of 6 rounds each.