Bfason is correct in that the reading of the quote in its original structure can lead to confusion in modern day readers. With grammatical styles being significantly different today than they were in the 1700's, often quotes can be misinterpreted, or just plain not understood. This appears to be one of those circumstances. On my first reading of Adam's entire quote, I was a little confused. On subsequent readings of the quote, I got the impression, much like Bfason, that John Adams was decrying the use of guns at individual discretion. Then, reviewing it more, and taking out unecessary portions of the quote for our purpose, I think that the shortened quote is being intellectually honest.
I looked over the web to try to locate a primary source, and save myself a trip to the library. About 90% of the quotations I ran across were in the same form as the SAF quote. I think this is mainly because the intitial quote is pretty convoluted, and does not lend itself to a quick reading. As a result, as is common practice, people have shortened it down -- while maintaining its meaning -- into an easily understandable quote.
The entire quote states that the use of arms, at individual discretion, except for in private self-defense, would destroy the constitution. Furthermore, the Militia should be created by laws, governed by laws, etc... In other words, we don't want paramilitary groups running around who answer to no laws. John Adams would have disapproved of the Fedayeen, is my reading of this.
So, one way to read that is that guns are bad, except when used for private self defense, or in a militia. Or, that guns are good for self defense, and legal militia's, but should not be used willy-nilly by anyone who has a problem with their neighbor.
There are only so many uses for guns. Self defense is one, hunting is another, citizen militia's are another, and crime is a pretty common one. Adams addresses the use of guns, then puts in the caveat that a legal militia was okay, and that self defense was okay. I doubt Mr. Adams was anti-hunting, thus leaving the only potential gun use -- for criminal activities -- that Adams did not specifically address, appears to be the one he was decrying.
Finally, the way the quote was originally given would be like me saying "you must not play computer games between 5:00 am and 4:00 pm." A reasonable interpretation of that quote would be that I could play computer games between 4:01 pm and 4:59 am. The common use of that Adams quote is similarly reasoned. He says that guns can be used for self defense and legal militia's, but not for other individual discretionary reasons. Or, as the quote says, "...arms in the hands of citizens, to be used at individual discretion, EXCEPT IN PRIVATE SELF-DEFENSE (emphasis added)...is to demolish every constitution, and lay the laws prostrate, so that liberty can be enjoyed by no man..." Or, as the common interpretation say, Adams thought that guns can be used in self-defense.
I do agree with Bfason when he writes that SAF should not be the end-all be-all for Second Amendment debates. Indeed, no one organization can be. And, this is not meant as an attack on anyone's reasoning. I am curious if anyone's interpretation of this quote, and it's common shortening, is the same as mine. Please let me know.