I just checked out the Bengal website. Their bullets in both .417 and .459 look great and at a good price. I've never loaded cast before, but am now considering it. I guess they're sized slightly larger diameter than jacketed? Any bullet lube required? Thanks!IMO it is useless to chase velocity in a DG cartridge. All you get is increased recoil. If you load that quality 400 grain bullet at 2250 to 2350 fps it will do everything needed without drama.
The cost effective solution to practice rounds are cast bullets and Accurate 5744 or Trailboss powders. Bengal bullets offers cast, powder coated and gas checked bullets for the 416 in two weights and they are very reasonably priced. Others offer cast bullets as well.
I use CCI 250 primers loading hunting cartridges for my 404 Jeff without any problems. For the reduced cast bullet loads, I use Rem 9-1/2 or WLR primers.