Quoted:
Is your new VLTOR sitting on the same receiver extension (buffer tube) as the CTR was on?  It sounds like the carrier isn't properly aligned in the upper, but I can't picture how that could happen.  The bolt catch doesn't work even if you manually apply it?  That's bad, and again, I can't see how that could happen, even with the thought that the receiver extension was somehow goofed up.

Quoted:
Here's the story. I recently changed out the free float handguard and stock (switched to a CTR from a VLTOR ) and could not get the bcg to strip off a round on either a PMAG or metal mag.

The bcg will not stay back on an empty mag even when pushing in on the release.

Have you checked your bolt catch thoroughly? Not sure what to look for but, just make sure it's functioning correctly. Do you have another lower or upper to test out?

I recently replaced the buffer retainer (and spring) and checked to make sure just the lip was being pushed down by the buffer tube. I lubed the bcg and release (they weren't very dirty) and still cannot get the bcg to lock back. When I release the charging handle on an empty mag the bcg moves forward but does not go all the way -- there is about a 3/4 inch gap. When I pull the trigger the bcg moves forward but still has a 1/2 gap.

Have you checked to see if there are any obstructions in the barrel extension? One time, there was a popped primer that was really smashed up and wasn't visible by a quick glance but, after really checking, it was lodged on the bottom right of the extension. Just throwing some ideas out there. Hope you get it figured out.

I  appreciate the help and advice!

Thanks

Ed