SPRINGFIELD — State lawmakers are taking aim on various firearm enhancements after a Las Vegas gunman used such an enhancement to kill 58 people and injure more than 500 last week.At least three plans percolating in Springfield would ban bump stocks, devices that drastically increase the firing rates for semi-automatic weapons.House Bill 4112, sponsored by Rep. Scott R. Drury, a Democrat from Highwood, would make the sale, manufacture, transfer or possession of such trigger modifications a Class 2 felony, punishable …