I shot the 300 gr smk to fireform my brass and they shot .5 moa at 100 yds. I would think you'd get similar results with factory ammo. Only dif is I jammed the bullets into the rifling to hold the case back against the bolt. You wouldn't have this with factory stuff. May work great but you could have some misfires. Kirby may have tried it or know someone who has so he may be able to answer this ? Better than I can.