JAF said:
I think the only drawback is that you would have to practice a little more with the pistol, but I wouldn't count that as a draw back
Well, there is also the matter that a brand-new AR-7 is about the half the price of a new MK-II. The law is also more strict on handguns in some areas.
And if you have relatives who might not be into shooting, I would also imagine that there is less change of self-injury using a rifle. If you are not there, would you rather have your SO handle a pistol or rifle?
But with that being said, I would love to add a buckmark to my collection. But I first have to grab the M6 that I saw a couple of days ago. Those things are harder to find...