I doubt it twice as much of the same powder, it would have to be different mate.
I definitely would prefer the stronger cartridge so look, if it helps I can get rid of them for you. No seriously, I don't mind. Send me a PM and I will arrange a courier to collect them not a problem ?.
Joking aside. Eley are not the company they use to be. If they have screwed up and double dosed the charge they need to know! Or, it could be someone else is doing their 410 ammo now!