I don't know how everyone else does it... (And not sure I want to)
I have two die rings precision ground out of carbide.
For my .308, The top die gauge is .3085" anything larger or out of round DOES NOT fall through to the next ring, is set aside in the 'Oversize' bin.
The top die has a slightly rounded mouth because carbide can have an incredibly sharp edge.
There is about 2" between dies so the longest .30 cal bullets can clear the top die, and my fat fingers can remove that bullet from between dies.
The second ring is exactly .308" in diameter, anything undersized falls into the 'Undersize' bin.
This die is specifically taper ground to mostly match the ogive of low BC bullets.
This keeps the dies from dinging up the bullet when dropped 2".
This gauge sits on a stand that straddles common plastic bin boxes to make live easier.
'Swipe Left' for oversize, 'Swipe Right' for First Quality match & bench rest bullets, drop through are undersized.
Anything that passes through the first, gets stopped by the second is a pass and goes on to weight check.
I have exactly the same gauge in .223, .224 and most calibers I've loaded bench ammo for.
It's my experience that slightly oversized bullets still shoot pretty good, grossly oversized or out of round do NOT produce repeatable results.
Out of round is almost always a core shift, and it's not hard to figure out how that screws things up.
In my experience even slightly undersized doesn't produce repeatable results, you have to work up a load specifically for the grip of the rifling an undersized bullet produces.
I would NEVER rely on ANY brand of bullet for a standard!
Once you start measuring properly, with an accurate tool, you will be shocked how under/over & out of round a lot of bullet brands are.
Here is a hint, a lot of 'Match' grade bullets... Aren't.
When you buy those high dollar target bullets, keep in mind there are some 'Hunting' bullets that are equal to, or surpass the 'Match' bullets, AND, they have a second purpose, 'Hunting'.
I'm not going to badmouth any specific brand, but I will recommend Hornady ballistic tipped 'Varmint' bullets, which WILL put a 10 round group under a nickel or dime @ 100 yds. (.224) without too much load development time (and a good barrel).
I don't throw out bullets that don't make benchrest or high match grade, these are practice, range and general blasting ammo fodder.
Hunting rifles won't know the difference, but your bench shooting will show you the difference, and you don't hunt with 'Match' bullets anyway.
There is no earthy reason the die gauges need to be carbide, I used it because it was here and incredibly wear resistant, I only wanted to make the gauges ONCE.
