I can't seem to do this.

My TGP will not lock onto anything while I am on the ground eg buildings, tower, hangars.

This guy does it in this video:


But I notice he locks onto a specific vehicle? Could this be the trick?

Probably...vehicles are easier to target than buildings.

FWIW, I wait until airborne to boresight. Just select a target on the way and designate as STP 15 in recon screen and when I am approaching the area I just call up STP 15 and set AP and do my BSGT in around a minute or so. It's just easier for me in the air than it is on the ground.

$0.02

Thanks - that's a good idea adding the extra SP, will try that...

Do you know if there is any way to release the Mk 82 AIR as slicks - changing jsut to nose fuse doesn't do it - or is this not modeled in BMS?

Mk82 Air and Snake Eyes for high speed low delivery.

Just use the Low Drag Mk 82 if not in the above profile.