I've used Blue Dot for reduced loads in a bolt action 308 Win. my load is 16 gr of BD with a Nosler 125 gr BT and F- 210 primers I don't recall the COL. The accuracy surprised me with groups 3/4 to 7/8" at 100 yrds.
The load density is about 45% so a double charge is possible, The big pain with reduced loads is they require some serious elevation an windage adjustments.
A big plus for this reduced load is it is clean and cool, little barrel heat and minimal barrel fowling.