Testing a variety of .177 slugs advertised as being suitable for sub 12 ft lb rifles, but are they any good?

On test:
JSB Knockout @ 10.03 GR
ZAN Slug @ 10 GR
ZAN Slug @ 13 GR
Wildman Slug @ 11.8 GR
QYS Magnum @ 13.2 GR (yes, this is a pellet, I know)

*additional note following some feedback... the testing was done using an "off the shelf" rifle with no power tweaks or modifications whatsoever.