I knew ATF kept some statistics. They do not publish exact models but do publish numbers of handguns manufactured in a range of calibers. They also publish the number of each caliber range made by each manufacturer. This doesn't directly answer the question about the 10 most common semi-autos but thought it was interesting. The following is for the year 2004 (the last year available) and is found at
http://www.atf.treas.gov/firearms/stats/index.htm.
The ATF had categories for pistols, revolvers, shotguns, rifles and miscellaneous firearms. I would assume all, or at least the vast majority, of "pistols" sold were semi-autos.
Pistols
TO .22 caliber 211,473
TO .25 caliber 10,140
TO .32 caliber 32,435
TO .380 caliber 68,291
TO 9MM caliber 182,493
TO .50 caliber 223,679
A couple of observations on these stats. One is the popularity of the .22. The vast majority of pistols up to caliber .22 have to be .22 caliber. On the other hand, in the range above 9mm and up to .50 would include .40 S&W, .45 acp, .45 gap, 10mm, and a smattering of .50 AE. The .40 and .45 acp would have to comprise the bulk of this range. My guess is, however, that 9mm is the second largest selling caliber after .22s.
Next comes numbers from some of the largest manufacturers (pistols only, not revolvers).
In calibers up to .22, largest manufacturers included:
Ruger = 45,099
Bryco = 75,640
Phoenix = 7,453
Taurus = 8,133
Beretta = 27,667
S&W = 11,524
Arms Technology = 23,175
The Rugers and Smiths would be target and/or plinking pistols. Berettas might be both target/plinking and pocket pistols. The Brycos, Phoenix (Raven), and Taurus would all be small pocket pistols. I'm not positive but believe Arms Technology would also be pocket pistols. That's quite a few small .22s being bought for defense purposes!
These numbers don't include imports so Glocks don't show up.
