Even the crappiest POS can stumble through 100 rounds of practice ball ammo, esp. if it's brand new.
When I get a new pistol, I get 5 boxes of ammo, all different brands, and if I load for the caliber, I'll bring some shoot'emup reloads, too.
Point is, if you like it enough to shoot 300+ rounds in one outing, and it's reliable with all the brands of ammo, and consistantly accurate with at least one brand of ammo, it's a keeper.
Of course,the flinch monster sometimes rears his head after a couple hunderd rounds of magnum type loads, so accuracy testing after that would be kinda pointless, for me anyway.