Update:
Loaded up some 142 SMK (Out of Berger 140 Hunting VLDs) with Retumbo.
Here are the results.
4000', 35 degrees, no wind, 55% Humidity. 100 yards.
142 SMK at 3.10", 215 primer, 3 shot group, Lapua brass
54.5 Gr Retumbo = 2873fps 3 shots touching, ****Best Group*****No pressure...