From what I have read the recently imposed restrictions are to do with the frequency of shooting given an on going noise complaint and no long term fix which was not going to cost the Hall’s a significant amount of money to implement. Given that they don’t own the ground and are just leasing it...
Tried the Superfast 24g plastic(7.5)on Saturday. Felt very nice smooth recoil and broke the targets well. Local price was £264 similar price as my usual Fiocchi Fblu’s which I shot back to back. Fblu’s gave better target breaks probably due to their tighter pattern and harder larger shot (7) but...
I’ve still got a thousand or so Victory sporter fibre cartridges that I last picked up at Doveridge Clay ground a year ago. Don’t know if they still sell them. Definately don’t see Rio’s anymore but Jockers are still around and no longer at budget prices
Eley select also come in a 24g cartridge so logically that would appear to be your next step up.
Most brands have 24g offering which will pattern well and break anything within your capability. So enjoy your shooting.