Hugh,
Yes, it is the caliber in hand, but the one in hand should be the caliber with which you can put multiple rounds on target rapidly according to a well written SB article that I am too lazy to find just now. [Editor’s note: Firearms Training/Exercise #1] AND, in case you need a note for your wife on the annual purchase rate, the congressional candidate who will get my vote next week says “If you know how many guns you own (off the top of your head), you don’t own enough.”
To avoid cheap mags I just go buy one magazine a month. “Mag of the month” is what I say to the guy at the counter. He smiles for a number of reasons. – RV