Yes there is nothing can be done with factory ammo, but definitely anneal the 'good' cases before reloading, if H is a reloader. Cracking necks is not really an issue in terms of firing off the factory ammo, H doesn't say if it is every case in the lower barrel or just the odd one or two.

It really has to be an issue with a slightly larger bottom chamber combined with older brass or maybe as suggested a bad batch of brass. I suspect the ammo is much older than thought, may have been in H's possession for a length of time but when was the ammo manufactured?

A reloader could pull the bullets, save the powder, fire off or punch out the live primer, anneal the case necks and reload again; not worth it for any cartridge that is easy enough to get ammo or cases for!