No, it shouldn't.
Classic Pistols:
DD44: 50 power, low accuracy, fast, 8 bullets.
PP7-S: 50 power, medium accuracy, fast, -1 bullet.
CMag: 100 power, rail accuracy, slow, -1 bullet.
If you add PP7-U, you're adding 50 power, almost-rail accuracy, fast, which means it is Yet Another 50 (adding nothing) and obsoletes PP7-S since there is no tradeoff except for the bang sound, which isn't a big issue in pistols.
Ag7 is the only other pistol to consider, since Au7 and AuG have their own little golden realm to play in. Ag7 is 100 power, almost-rail accuracy, fast, and +2 bullets over CMag. That sets them on opposing parity: CMag is slower, but even with fewer bullets, reloads less often than a spammed Ag7, and CMag has the greatest penetration factor available, so it can hit through doors at angles the Ag7 can't manage.
On a related note, I am considering buffing DD44 again. Taking feedback from ragequitter Oil Leak, and general whining about DD44, I might find a way to improve it without throwing off balance, in a way that widens gameplay. Not sure yet what I'm thinking about, but something is floating in the back of my mind.