The man in the shop just handed me a box of cartridges and the magazine. No instruction was given or asked for. The first cartridge I attempted to load the wrong way and realised immediately it was the other way round which took I guess 10 - 15 secs. Thereafter I guess it was around 5 - 10 secs to load each cartridge. I would liken the task to inserting batteries to a TV remote. There's nothing remotely complicated about it. You would need to suffer severe learning disabilities to find any trouble with it as it's obvious and intuitive. The magazine is designed so you can only insert them the right way so even if you attempt to load them the wrong way as I did you realise in seconds they go the other way.
JB said he left the mag with 8 - 10 cartridges in. But for those who disbelieve JB, the perp would only be time pressured with the first load where the evidence supports June sustaining 6 gsw's and NB 4 gsw's which incapacitated them to such a degree the pathologist said if other shots hadn't supervened they would have died from these initial gsw's.
Your last paragraph doesn’t make sense
No-one’s suggested June and Nevill weren’t first shot 10 times between them
What’s THAT got to do with loading cartridges?
Besides, just because the perp, Jeremy Bamber claimed he’d left the gun in the kitchen (or the settle in the scullery, depending which lie you listen to), he would’ve lied about the amount of cartridges he said were in there too...
He is a liar, remember, Holly