As a general rule I've found alot of 452's, 455's and 457's really like SK Standard Plus, SK Rifle Match and Norma Tac.
Regrettably, there’s no definitive answer to that question, especially in the middle grade grade lines. Lot to lot variations will drive you nuts at times. Those who really need consistent performance will get some ammo from a source that lists lot numbers and then buy a bunch of a good lot, but I don’t see a 457 as deserving of that. ..
During the last 25 years , I have owned at least a dozen CZ 452 rifles which have all been a least MOA accurate with some type of ammo. From my testing ,what I have seen mirrors the above two posts.
I currently have four 452 sporter rifles and a lone m457 American sporter (my first in that action design). From my testing if you want true match grade accuracy, try RWS R50/R100. High end Lapua loads or Eley Tenex / Match.
The CZ 457 Varmint -while a heavy barreled rifle- does not have a true match dimension chamber. Very often with non- match chambered rifles mid grade ammo will shoot as well as the higher end match grade stuff . The CZ bolt guns are famous for that when shooting $8 to $10 per box SK Standard and Rifle match, so do not ignore those loads in your search.
The CZs also seem to like RWS made ammo which is also who makes the Norma rimfire line. The newly released Norma Match standard velocity would be a good load to try along with RWS Target or Rifle Match. I would also give some of the lower end Eley loads a try like Eley Club ,Target and TEAM loads which can outshoot TENEX and Match in some rifles.
My list for "bang for the buck" ammo for CZs would be -
SK Standard
SK Rifle Match
RWS Target
RWS Rifle match
Norma Match
Eley Target
Eley Team
