I sappreciate the help, guys. The hard numberds Gunter put up were along the precise lines of what I was looking for, but the perspective the UK gents provided was and is quite welcome.
I have always come at the issue from the POV of less gun control is better. (I've been arguing the case against gun control since I was old enough to form a coherent argument - sometime around age 11, over 40 years now.) I got into this latest argument on another site, where some dimwits were trying to make that cop in SC shooting a black guy in the back into another pretext for gun control and simultaneously dismissing as false the entire concept that privately owned guns do have an effect on the crime rate - i.e., lowering it. I have found lots of now-dead links to old articles (circa 1999-2001) in which the rise in UK crime and the then-recent confiscation of handguns were tied together. (I have time to research and write my rejoinder to those dimwits on the other site b/c I have article-posting privileges there and they don't.)
I understand the hazards of trying to prove cause-and-effect but also recognize that in the heat of debate (or even in the less-heated room of forming opinions) no one takes the time to parse out where the gaps might be. And I know how to construct a pretty solid case even when there are gaps.
I also appreciate that reasonable minds can differ and that the UK experience is quite different from the US. There's probably a series of books in there somewhere that I'll never have the time to read, let alone write. But I gotta fight my battles where I live.
And, for that matter, those Mass. laws are (along with much better rental rates) why I live in Maine and not Mass.
BTW, it looks like Maine's "constitutional carry" bill is likely to pass. It has something around 100 co-sponsors, last I checked.
Thanks again, guys.
