Small-base dies: what are they?

[xrMike]

I overheard a conversation at the range today where some guy was telling another that he should get "small-base" dies for reloading... What are they and when/why would you use them?

[fairfaxjim]

This was taken from another thread on reloading .223. I have a friend who uses a small base .223 die for loading for a semiauto that has a chamber that is on the small side. I also use that die to load for a .223 bull barrel rifle that I have that doesn't seem to like to chamber the reloads done with a standard Dillon .223 sizing die.

You will only need to use a small base sizing die if and only if your regular full length resizing die, when properly adjusted (screw down until it hits ram, drop ram, and screw down another turn at most), and the brass still does not pass a headspace gauge (or chamber in your rifle).

This rarely happens, and when it does, it is caused by brass shot from very loose chambers.

The original thread is here: http://www.calguns.net/calgunforum/s...small+base+die

[NRAhighpowershooter]

you would only really need a SB die if you are reloading for a semi-auto rifle with a match barrel... or a really tight chamber in a match barrel in a bolt gun...