I don’t think they do. I have some and posted a similar post on ar a while ago. I don’t have a .458 win at this time only Lott’s and was wondering if any one had tried it. Most replies reported 100 to 150 less than advertised velocity. While this is lower than advertised it should still kill everything. I am wondering if they have a tricked out test barrel lapped to max diameter and 26 in long.
Bill