i found a really good bullet for my .223 savage.. it really like this 68 gr. HPBT.. it has a BC of .355.... I just now found some berger 70 gr. VLD bullets with a BC of .437 ....Now does BC only effect the drag of the bullet? which would make its trajectory flatter or does it effect accuracy? Basically if i wanted to tighten up my group a little would the switch be worth the extra $12 per 100 bullets?