Not feeling well and sore from shoveling snow from the day before, I spent quite a bit of time yesterday checking out a number of other forums (pro-gun and survivalist) for info on why some gun owners feel it necessary to have high capacity magazines. While there were references made on the 3-3-3 rule which is supposedly based on FBI data that states that a majority of gun fights take place at a distance of 3 feet, are over in 3 seconds and 3 shots are fired, and a few posted that most gun owners will never actually need to fire their gun in a home or self defense situation, I didn't see any post that provided evidence backed up by data or studies that showed that there was a legitimate need for high capacity magazines for home and self defense. Just personal opinions such as one can never have too many guns or too much ammo and arguments based on hypothetical situations rather actual events.
The hypothetical situations being where an individual faces an attack by a large number of well armed bad guys at one time or a series of smaller attacks over a period of time during a natural or man made disaster. But none of this was based on actual events other then in one forum it was mentioned there had been a member who lived in NO during Katrina and used his gun on a number of occasions to ward off looters. It was not made clear in the posts I read as to what type of gun this member supposedly had.
Actual situations that could have been referenced but weren't are those cases where an heavily armed individual in a home or building faces off against the police or a swat team. This would be similar to a hypothetical scenario where a homeowner is confronted by a well armed gang. But I'm unaware of any actual case where the situation turned out well for the individual. He was either killed by the police, surrendered or toke his own life. This despite being heavily armed himself and having a large amount of ammunition.