Like thread title asks, are small base size dies needed for .458 socom?

There's at least one company that makes them, but not apparently common.  Kinda wondering if it's just already factored in to all dies since it's predominantly an AR action caliber?

Either way, brass is ordered and starting to build a rifle.  Dies are next on the list.

Not needed.

Buy a Tromix bolt/barrel combo. Don't forget to get the ejection port opened up.

Redding standard size die, Hornady seater w/ micrometer stem, and Lee FCD if you want to get Gucci with it.

I also use a Lyman M die to bell the neck a hair but a Lee universal belling die would do the same thing.

Flat base bullets (especially lead) can be a bit finicky without a tiny bell.

I have and always will use the hornady dies I have.

Never needed a small base die, or any sort of fancy tools for 458 socom.

It uses the same shell holder/shell plate that 45 acp, 308, 6.5cm, 30-06 and a bunch of other rounds use.

I have never needed to trim a case. They all stay about the same length firing after firing. Case failure usually happens at the neck/shoulder. They crack.

I load it on my 550, I did end up having to double up my powder funnels. The 45-70 powder funnel works if you double it with a 308 funnel instead of buying the fancy one from dillon. It also makes a good flare.

I got a lee FCD for it and it works like a charm in station 4.

Took my deer last year with it.