I also agree that those caps on the jacks are dust/retainer caps and not to be used for terminations.
-Hal
Interesting. ICC, ATT/Lucent/Avaya, Ortronics, Suttle and even Leviton provide instructions right on the packaging showing the use of the caps to terminate the wires. The only mention I've ever seen of them being used for retention/dust protection (?) has been as an optional item that is sold for use on patch panels. In my 25+ years playing with these things, I've never used a punch tool on a single jack, not even a non-impact or one on a low setting.