Re: Bullet tip modification
At 600yds the reduction in BC will give you a velocity reduction of about 200fps. Winddrift will be increased by 6-8 inches. Any increase in accuracy from getting closer to the lands will be lost in the susceptibility to the wind and possibly bullet imbalance. All of this is so you can use your magazine and have avavilable a second and third shot? It seems to me you are trading three inaccurate shots for one accurate shot.
Other consideration is all of this grinding of lead. With young children around, lead dust and shavings and filings need to need to be avoided at home. CDC has lowered the blood lead levels for children to about 10ug/dl and there are still adverse effects at this level.
The Smokin Fur Rifle Club