Please excuse my ignorance. I am looking to build a 284 straight win for competition. My problem is understanding the brass and dies required. If I use Lapua 6.5-284 and neck up what caliber dies do I use and are they standard? I have been told the Lapua dimensions are different than Winchester brass? I thought I could just use standard 284 win dies to size body, neck etc. I do plan on using Lapua brass. I realize that the reamer I choose should better match this brass? Please advise.