The cups should not have play. The bottom bracket itself might have, until tightened by the cups. Since Bare Knuckle track frames are built by an Italian frame builder http://www.labrakeless.com/collectio...frame-fork-set the threadening of the BB-cups might be Italian (however, I don't know for sure). Italian style R-threaded adjustable BB-cups often loosen (particularly if it is not the original factory install anymore, or never was); a similar effect might happen here.
In contrast to FBinNY I think torque plays a role here and I would consider using thread lock on the right cup and tighten both as much as the aluminum (of the cup) allows.