Karl,
Your best bet would be to work up slowly watching for pressure signs. All 444's are made to take SAAMI max pressures that the 444 cartridge generates. When you get into the realm of hotter loads beyond this, you are basically on your own.
The 330 shouldn't be a problem if it is driven fast enough to stabilize. I myself, tend to go with the 280 WFN. Good balance of weight, energy and velocity. Micro-groove rifling presents no problem as long as the bullet fits the groove/throat diameter properly.
There is a tendency today to go by supposed gun strength rather than the max pressure the cartridge is designed for. This can be at times, a dangerous pursuit with accelerated gun wear on one end and catastrophic failure on the other. Only you can make that decision for yourself.
FWIW
Regards and welcome to the forum!
