Reply #68: It would seem that they did [View All]

[Euromutt]

Since the statistics reportedly indicate that post-ban, use of "assault weapons" in gun crimes dropped, while use of "high-capacity" magazines increased.

Oh, wait, here's the executive summary of the actual report (http://www.sas.upenn.edu/jerrylee/research/aw_exec2004.pdf):

• AWs were used in only a small fraction of gun crimes prior to the ban: about 2% according to most studies and no more than 8%. Most of the AWs used in crime are assault pistols rather than assault rifles.

• LCMs are used in crime much more often than AWs and accounted for 14% to 26% of guns used in crime prior to the ban.

<...>

• Following implementation of the ban, the share of gun crimes involving AWs declined by 17% to 72% across the localities examined for this study (Baltimore, Miami, Milwaukee, Boston, St. Louis, and Anchorage), based on data covering all or portions of the 1995-2003 post-ban period. This is consistent with patterns found in national data on guns recovered by police and reported to ATF.

• The decline in the use of AWs has been due primarily to a reduction in the use of assault pistols (APs), which are used in crime more commonly than assault rifles (ARs). There has not been a clear decline in the use of ARs, though assessments are complicated by the rarity of crimes with these weapons and by substitution of post-ban rifles that are very similar to the banned AR models.

• However, the decline in AW use was offset throughout at least the late 1990s by steady or rising use of other guns equipped with LCMs in jurisdictions studied (Baltimore, Milwaukee, Louisville, and Anchorage).

Emphasis in bold mine. So to determine "LCM" use, they relied on a sample of four cities. With the kind of sample size, it's lot more feasible to plow through the local PD's records to determine mag capacity, rather than having to rely on the FBI or ATF data. Of course, with a sample that small, the confidence interval gets pretty wide, i.e. there's a wide margin of potential error.