I've loaded Trailboss with my 550 and it meters quite well. 12gr in 8x56R, 205gr bullet for my styer M95, about 1125fps and 10.5 for 308, 168gr, 1045fps.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: danny.k</div><div class="ubbcode-body">Works great on my 550B when charging 10.0grs for my 308win sub-load.
Throws nice even charges