The AP2/CB/MB irons are the "traditional" lofts prior to companies lengthening their shafts and making the 6I the same loft as the former 5I. The number on the end is just a number. The pro's have a 170 yard iron and a 180 yard iron, not whether it is a 6 or 7 iron. The changing lofts are primary for marketing to say this 6I is longer than that 6I. The P in an AP2 is 47 degrees so you don't need a gap wedge, and most of us, there is a "terminal" loft that we can hit before moving to a hybrid, not a club number.
That said, you can adjust the loft by 2 degrees without cracking the finish on the hosel.

If you are playing well I wouldn't change the lofts. It is about how you play not the club number you are playing.

I recently had a shot of the new Wilson 7 iron (I was picking up my ts2 3 wood from the pro shop at the time and they asked me to try it). 193 carry with a 7 iron that was the loft of my 5. What is the point?