Better in which regards? Both are high quality pistols, which fill a specific niche. If you wanted something for concealment purposes, the Walther would be a good choice, although Glock does make subcompact pistols in .40. However, the PPK would be a bit easier to control than the Glock 27, which is going to have considerably more recoil and muzzle flash. The Glock has no exposed hammer, which helps avoid snags on clothing as it's being drawn.
Ultimately, it comes down to what you're comfortable with, and which one suits your specific needs better.
the 380 is a 9mm short
No. 10mm is close to .40 cal, smaller than .50 cal.
A Glock 22 (.40 cal) and a Glock 27 (.40 cal) as a backup.Actually the standard NYPD sidearm is a Smith & Wesson 5946, Glock 19, and formerly the SIG-Sauer P226.
For a basic Glock 21, new in box, between $600 - $650.
NO
No.
No.
100-400
No, none do.
Let a gunsmith do it.
You would have to define best- what what use.
The case of the 9x18 cartrdige is 1mm longer and the slug is slightly wider. In metric .380 ACP is 9x17.