There's 6.5 Jap data on Hodgdon's site. 100, 120, 140 and 160 grain bullets. Only Hodgdon powders though.
I'll have a look in my old Lyman manual and post tomorrow.
You can neck size only using brass fired in that rifle only. BNIB brass requires checking for length, chamfering the case mouth and FL resizing first.
The 6.5 Creedmoor and Swede Start loads are close to the Jap Max loads. The Creed's SAAMI pressures run to 53,000 PSI/63 CIP. No SAAMI PSI ,but the Jap runs 43,000 CIP. No comparison.