Originally Posted by SBruce
Compressing the powder will be determined by the powder you're using and the charge. Is it slightly compressed with your current seating depth?
Another variable that you could play with would be powder itself. I was instructed to use Retumbo in mine, so that's what I started with and still using.
Right now seated at 3.681, it is NOT compressed. I'm using Hodgdon H-1000 -92gr. for the Berger 300gr.
I tried Retumbo. It was OK but not as good as H-1000 IMHO.
I think maybe, in addition to everything that's been suggested so far, I may
reduce the amount of powder incrementally. Maybe by doing so I can get even
tighter groups at 100 yds.
I chrono'd my loads this past Monday. All with Lapua Brass, Fed. 215 Primers and H-1000 powder.
SMK 250gr. / 100gr. seated at 3.680 / 3215 fps (this was a good load as far as groups)
Berger 250gr. / 100gr. / .010 off lands / 3155 FPS (not good grouping)
Berger 300gr. / 92gr. / .020 & .025 off lands (groups were so-so) 2850 FPS