KyFarmer ... your 405gr (Hollow or flat base) will produce nice groups out the BC.
I dug into my reference database and here's the recipe I used for smokeless:
25.4g of XMP-5744 in WW cases with a CCI BR-2 primer. This gives 1299fps out of the BC with an SD of 3.31. ES was only
8.45!
I can help you out with an other excellent shooting bullets in the 500 to 535gr ranges, but you'll have to load the cases with 'orginal gunpowder'
I'm a 98% BPCR shooter. The bullets are Lee 457-500-3F with 65gr FFg: and both the Lyman 457123 and Paul Jones Creedmoor [+ or -] 535gr with 70gr FFg. I see no reason why these 3 bullets would not shoot accurately using smokeless ... 3031 - 4198 and 4895 powders with an alloy of 1:20. Start with the minimum charges for the bullet weights and work your way up with 0.5gr increments. Will cost you some range time but it's well worth the effort to determine what your rifle likes best. Personally, for the 535gr bullets, I'd start with 4895 powder
Good Shooting!