Thinking of doing one too...I have a finicky 30-378, that may get traded- (shoots awesome with 168's and 180's--struggles with 210 bergers and 190 bergers--and doing a 30 Nosler on a tikka 695 I've got laying around...
I'll be using a Tikka T3x action. Problem with the tikka is the COAL is limited by the short length of the opening on bottom of the actions receiver -- even with AI mags a coal of 3.4 barely clears the front of the feed ramp.
Berger has load data for the 30 Nos for the 215 hybrid (unpublished but avail if you call) with a coal of 3.47 -- def better than what you can get with SAAMI coal of 3.340. HOWEVER, I found a work around.
I've designed a custom bottom metal that bumps the mag well on the bottom metal back 0.050" towards the trigger housing that allows a COAL of 3.500+. Still not quite as good as the 3.6+ you could do with a wyatts extended using a diff action -- but for my goals and purposes I'm happy with it.
This bottom metal is patterned off the short action Tikka CTR DBM that runs trg22 mags -- essentially a CTR bottom metal for long/mag cartridges. Instead of AI mags, it accepts the TRG42 magazine. I've had a prototype 3D printed in plastic and the fit and feed is far superior.