Let's make sure we are all talking about the same thing!! As we see in this (not so nice) Lightning bug, the weight is SQUARE, not round.http://cgi.ebay.com/VINTAGE1928-VIBROPLEX-BUG-TELEGRAPH-KEY-MORSE-CODE-CASE-/110655170246?pt=LH_DefaultDomain_0&hash=item19c38fe6c6
The "wpm" is based on the speed of the DITS. Of course with a bug you can have 40 wpm dits with 10 wpm dahs, giving you "something" like 20 wpm that is nearly impossible to copy.
If your dits are 27 wpm dits, then your CODE should be 27 wpm when you send it (check the speed of your dits with your electronic keyer). Is this what you are talking about? When the keyer is set for 25 wpm, the dits are 25 wpm and you are also REALLY sending the word PARIS about 25 times in one minute.