r/CZ457

Question, I just picked up a 457 MTR and I'm using 10 round polymer CZ mags. I am experiencing some trouble to get the mags to "click" into place. They fit fine but it takes some attention to make sure they are pushed in all the way to the final "click". It also the click doesn't feel real solid, but the mags don't fall out unless I don't get that last "click".

Is this common? I thought maybe my two mags are worn and don't allow for enough engagement to easily lock in. Would an extended mag release help?

Title pretty much says it but which ammo do you use for practice or plinking? I am currently testing Eley for comp ammo but looking for something that I can buy in bulk for practice that isn't absolutely inconsistent. Previously tried SK but the rifle didn't like it. (457 At-One Varmint 24")