On rimfire central some were saying to shoot 50-75 rounds of the same brand before testing groups.
I have 700 rounds down this barrel now and have been shooting Norma TAC22 for the past 400+ rounds now.On rimfire central some were saying to shoot 50-75 rounds of the same brand before testing groups.
Both my CZ452 and CZ457 like SK Standard Plus 22LR ammo. They do pretty good groups (<0.5 at 50yds 10 rounds) with most quality ammo within 1080 plus or minus 20 fps. Those that stay closer to the 1080 hold at distance too. Normal match ranges are up to 300 yards, but occasional to 500 yards.(this shooter can do 3 out of 5 on 24x24" plate 7 out 10 36x36" with old eyes and a bit shakey, rear bag n bipod) An opinion only - cutting down the barrel, unless damage or bent alone with not improve groups like better ammo.I have a CZ 457 with a 24 1/2 " barrel. I cannot get it to shoot with my CZ 452 Varmit. The 457 shoots the CCI sub sonic slower than my 452 Varmit. I am wanting to start by cutting the barrel to 20", Try it and go to even shorter if I have to. It sometimes takes shorter barrels to get the speed right for barrel twist and ammo to shoot good.