C Z is due to come out with a short(.308 Win.) based action which will accomodate the new generation of short magnums. Hopefully this action will also be offered(my wish) in conventional calibers: .308 Win., .243 Win.,.22-250 Rem., etc. thus allowing a shorter bolt travel while cycling(faster that's all).
The CZ-550 series has a Mauser based extractor, this extractor system is well known for its extreme strenght & positive extraction but was never made as to cycle from the top. Every cartridge has to come from the magazine box. The .303 British/Lee Enfield has but a small extractor which leave dangerous big game hunters not wanting it.
If you want a push-feed system go with Remington ,Sako, Tikka, Savage, etc.
All the best,
Fred