Aren't you the lucky one! I have an old advertisement with that 401 Powermag in it and drooled over them when I was a kid. Saw one in a pawn shop when I was 17. Too young to buy one, and would have been in big trouble if my parents had caught me 'in a pawn shop for any reason'. BUT, the shopkeeper let me hold me....ah, the memories.
You state you have a .405 bore and your mold drops .4035 so I don't believe you would be wanting a .403 sizer - rather I believe you would be wanting a .406 sizer and 'bump' the bullet a bit as you lube it. However, you don't state chamber exit dia, so this may be just rhetoric, as your chambers pretty much are the limiting factor first, followed by the barrel. You don't state what your alloy is - WW drops a larger bullet than Linotype, by several thousandths, out of the same mold and, if water-dropped, are plenty hard enough for magnum revolver applications.
Alternately, have Veral cut you a proper mold.
My local distributor is Buffalo Arms in Ponderay, Idaho. Their catalogue on pg32 lists 401, 403 and 406 dies from Lyman, and states that custom sizes are available for twice as much.
www.buffaloarms.comI'm thinking I may have a .406 sizer in my stash. Memory is telling my I got one for my 40-82Winchester Model 1886. However, I don't use it as my .410-sized bullets for my 41Mag work just wonderfully in it. It slugs a touch over .408 - a tad on the large size. Then, you would have to sell me your revolver, which doesn't just solve your problem, it eliminates it! LOL! ...BUT, does give me a problem as I am on a moratorium of new purchases. [Of course, this would be a used purchase, and I'm not sure if that would remove it from the restrictions set by the moratorium.] Seriously, if you find this might help you, let me know and maybe we could come to terms on the .406 sizer - I will take a look for it, just in case.
Regards,
Sweetwater
Regards,
Sweetwater