Weapons signed out by authorised person, two qualified intructors (SIs - SAA not required for escort) in the vehicle (assuming less than 30 weapons) - ammo in second vehicle, also 2-up.
I believe you can get away with only one with the ammo if that person is correctly qualified (think county staff can do this)
I also believe there is meant to be a sign carried in case you break down to notify police you are carrying weapons.
Could be wrong though - normally the DC deals with the rules, I just sit there as escort
Apparantly it's a sign to be used if you break down, to notify passing coppers to stop (along with the panicky call to the local plod saying "I've broken down with weapons ") - not seen it as it has never been in the vehicle when we pick it up...
LANDSO 2901 will give you all the information you want but basically:
under 10 weapons - one vehicle, driver plus escort
Up to 50 weapons - two vehicles, driver and escort in each
Over 50 weapons - police and land get involved.
You need authority to move them and a sign marked FAO Police with information on the back of it.
All this null and void if weapons are issued individually. Cadets can not act as an escort, pretty sure escorts need to be security cleared.
1980s a certain junior officer turned up with his car boot full of slr's a couple of gpmgs and tons of blank pyro.
Our Cadet MAJ also ta major went berserk phoned the adj of the regiment.
Was even more angry when "the cav replied he's a good chap I'm sure he'll bring them back on monday"