Just seeking some advice regarding load development...

26" ER Shaw 1:8 twist Heavy barrel
H4350
123 Lapua Scenars
Lapua Brass
FGMM 210 Primers
.020 off the lands
Shot at 100 yards...

My reloading skills may have a little to be desired hence the SD's being all over the place. My lowest SD @ 43.9 was all over the place vertically. I'm thinking 44.1 to 44.3 is going to need further testing. Any suggestions would be great.