Why do folks over-think cast, when really the most simple actions often produce results that are good enough, or GREAT!
Things like "Hard Cast"
Hard cast was originally designed by commercial casters for SHIPPING cast bullets so they would arrive undamaged.
if you cast your own, you can go much softer, for less risk of leading, and often a cost savings.
When first thinking of cast... one should think SOFT and only go harder as the pressures go up.
Sizing
folks get caught up in sizing, when what often works great is a bullet that has a slight friction fit in an unsized, once fired case. (no crimp/flare)
if it fits in an unsized case, and can chamber, it WILL shoot, and probably as good or better that fiddling with sizing etc.
Bore/Groove size should be ignored, except in the case of a rifle bullet designed as a "Bore Rider". then the "bore" diameter IS important. (I have 3 45/70's who's bores run 0.4555". To date, I have found NO "Bore Rider" designs that have a nose that fat.
When first thinking of cast... one should think UNSIZED and only size as necessary to get a bullet to fit in the case and be able to chamber if your particular bullet is too fat. Size it to fit the unsized case, NOT the bore/groove/throat.
some guns simply won't allow a fat bullet to fit/chamber... in those, most experienced cast shooters would recommend to open the chamber neck to allow the fatter bullet, or if the throat is the restriction, open the throat. (Another option is to shoot Black Powder.) This allows you to work the gun once as opposed to working EVERY BULLET.
Indeed, some VERY successful target bullets are multidiameter, and cannot/SHALL not be sized.
Lube
Lube is a gasket, mostly, with its purpose to seal the bore. lead alone IS a lubricant. Tumble lube works OK as long as it is an appropriate mix for velocity. TL mix also works just fine on GG bullets. and GG lube can and is used on TL bullets with success. Again, it has to do with the appropriate mix for the pressure.
EX// at TL Lee bullet, pan lubed carries as much lube as an RCBS single lube groove bore rider... and the nose carries NO lube. If lube was so important to lubricate the lead from the steel, the nose would be designed to carry lube.
Also, there are some bore riders with a groove diameter ring on the front of the nose for alignment, and NO lube.
Some very experienced muzzleloader shooters have NO Lube at all on their first bullet from a clean gun.
The "old wives tales" are truly ingrained in a lot of folks, and they make some things complicated, where simplicity is the rule.
Like sizing 1-2 thou over groove. As Gnoahh has stated, sometimes best to ignore groove dimensions as they are not relevant.
Another one that is still floated often: Seating deeper in a bottle neck rifle cartridge raises pressures. That one was debunked years ago, but some still hang to it.
To me, Casting is like working a new load.
Start LOW/SIMPLE and work your way UP/COMPLEX
This is why powder coating is so promising... it removes one variable: Lube, and mitigates hardness, allowing a MUCH softer alloy.
Heck, some folks are running Lyman 2 equivalent to 3000FPS with PC and nearly that in 30cal or bigger for impressive hunting loads.
and as Yondering has pointed out.... PC really is that easy.
Ok, I got my big boy panties on.... flame away.
