For all high velocity loads, ie: when getting up around 2,00fps and higher, I'd suggest LBT Blue lube.
I still have a bit of the original LBT Blue - the stuff that needed a heater for the lube-sizer. With heat treated 269gr. Lyman bullets sized .377", I was able to run just over MOA at 100 meters at 2,700fps - no leading.

500gr. bullet is heavy for the restricted overall length of 2.55", but should still be able to get upwards of 1,550fps - maybe a bit better.

I suggest Hodgdon Bench Mark (you'd use ADI equivalent) - I'm sure you should be able to do those speeds with it considering the OAL restriction - without the need for special lubes. Simple Beeswax/Vaseline mixes worked for me in .45 and .50 cal. rifles, right up to 2,000fps.

Sizing the bullets .001" to .002" over groove diameter is usually a good idea.