lapua vs winchester brass for 300 wm??

[30-06 boy]

i've been using winchester brass thats been sorted by wieght in my 300 wm.i want to tighten my groups up some more. not that they are bad,but everone strives for tighter groups. i see and hear from other long range target shooters/hunters that they use only lapua brass. my question is-----why is lapua brass so much better than winchester? will just switching to lapua brass tifgten my groups? jason

 

[dirtball]

This is something you probably do not need to worry about since Lapua no longer make 300WM brass. Those who have any won't part with it OR they want way too much money for it.
Dave