can the breech of the barrel be ground down to make a more positive ramp to eliminate jams? i have a 30 round mag that works most of the time but some times the tip of the bullit hits the rear of the barrel and stops dead. Its a 189 series and thier seems to be no ramp just 2 steps, cant i grind this to a 45 angle or add metal to it so thier no step to drag on. Is there any safety reason for this or does it just not work? why does every one tinker with the mags and nobody has tried this?