Re: 6X47 Lapua chamber reamer
Seat your bullet so the bearing surface/boat tail junction is just slightly ahead of the neck/shoulder junction of the case. When I do this with my 6-47, the OAL with Custom Competition bullets is 2.625" and they're just touching the rifling.
If only 1/8 of the neck is holding the bullet, you'll run out of neck before you ever get a really good load developed and drops figured. The throat on the gun will erode from firing and you'll have to seat the bullets out further if you wanna be close to the lands. I think 2.8" is probably too long.
You can send the dummy (loaded how you want it) to Pacific, or just call Dave and tell him your specifics and he should be able to go off of that.
Aim small = Miss small