H1000 and Retumbo both worked very well in my 7RM but Retumbo was best and more accurate. So, like already posted, a match made in heaven. But not really, it was made in my basement and proven at the Middletown gun range.
WW brass, 73.0 gr Retumbo, 168 Berger VLD, .010 off the lands. Rifle is a McMillan, Krieger, 26", Jewel, TAC300 by Stiller built by Dave Bruno.