Did a bit of reloading and testing on the weekend .
The best 400gr frontier load I got using my chrony was an average velocity of 2385fps from the 20" barreled Ruger Alaskan . Load was 78 grs 2208 fed 215m primer. There was no sign of pressure or hard bolt opening etc. This was a safe load in my rifle with this particular design bullet. Work up to it in your rifle if you want to use it. The frontier bullet has a 2 diametre tip. The first .400" of the bullet tapers to .410" then has a shoulder which steps up to .416" This gives a bit of a jump into the bore before the full diameter reaches the bore. I would imagine this was designed this way to help keep the pressure down. Seems to work okay.
From a 20" barreled .416" I am fairly happy with the velocity now just need to try it on game.