Best ammo for my cz457 varmint - Eley Ammunition Eley Ammo Club .22lr 40gr. Round Nose

Eley Club shot below 1/2 moa in my CZ 457 Varmint. Accuracy improved after reducing the headspace by 0.004 inch. Eley manufactures their 22lr with the thinnest rim thickness allowed by the European CPI standard, thus it performs best with in firearms with a tight headspace and best in firearms with a headspace tighter than SAMII specifications. Eley Target performed equally well but has greater lot to lot velocity variation. Personally the extra 2 to 3 cents per found additional cost is worth it to me to avoid having to make trajectory adjustments every time I change lots. This is the only ammo shot in my rifle the past 6,500 rounds but I've got 1,500 rounds of Eley Target as a backup in case I run out of Club.

Note, lots of CZ457 shooters find SK or Lapua to work better in their firearms. I had feeding and ejection issues with both of those brands and neither shot better than CCI standard velocity in my 457. Lapua and SK use the thickest rims allowed by CPI, thus it's unlikely the same rifle will shoot Eley and SK/Lapua equally well. The Caveat being a rifle with the headspace set at exactly the midpoint of the CIP allowable headspace.