Cavity Back Bullets have shown to be very good at pressure handling.
That being said please use the starting load from a similar weight all copper monolithic projectile.
Start with known book starting loads, always, without exception!!
Use the data from your powder manufacturer as a starting point.
Always check distance to the lands when loading longer than SAAMI specs!!!
We have no way of knowing the free-bore in your barrel in any caliber.
Our bullets are designed to be able to run longer than SAAMI specs.
It is up to you the reloader to make sure there is clearance to the lands in your chamber.

To save bullets you can do a single load ladder, typically in .5 grain increments.
Watching for pressure on each load.
At the first signs of pressure in YOUR barrel DO NOT go higher.

Only in some cases with limited capacity have the MKZ's shown the ability to run the same charges as like lead bullets.
Such as the 120 MKZ 6.8 and the 120 SST.
It CANNOT be assumed this is the same with all bullets in a particular caliber.
Loads must always be worked in YOUR barrel.
We cannot stress this enough!!!
DO NOT run someone else's load without working up to it!!

If you are unsure of anything please DO NOT proceed.
Contact us at support@cavitybackbullets.com or ask in this forum.
We check our section multiple times daily.

Thank you
Robert
Cavity Back Bullets