.223 Rem reloading

[bodiebill]

Anyone have experience with RCBS Small Base X-Dies for .223 Rem (5.56x45mm NATO)?

RCBS recommends that cases resized with Small Base dies not be used in bolt action rifles? Can anyone explain why?

I use a Wilson case gauge and find that some cases that pass this gauge test are tight in my Rock River Arms Wilson- barreled Wylde Chamber. Puzzling. Apparently the Wilson case gause is not a sure-fire final gauge.

Information

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[JBS]

I only use the RCBS small base die ( first sizing ) to process range pickup to correct for an unknown chamber. I only use Redding dies to process my match brass. Frank White chamber.

A small base die will “work” the web of a case. This area along with the case head is not annealed it is hardened. If repeatedly work by a small base die it will cause insipient head separation if the case is fired in anything other than a tight base match chamber.

[Kirk]

I use both the Garand & an AR15 and use the standard base dies: RCBS X-Die & Lee dies. I use a case gauge to check sized cases plus check a few by chambering them. I have never had a case fail to chamber or fall into the case gauge (except those with a damaged rim) so I think the Small Base dies are not needed. And as JBS says, they needlessly overwork the area around te web which will shorten case life.

[rider]

"Apparently the Wilson case gause is not a sure-fire final gauge."
It always has been for me. Are the cases all trimmed to length? Is the chamber clean?
Why not contact Rock River and tell them about it?

[John Kepler]

OCCASIONALLY, you'll get an AR barrel (or any gas-gun barrel) with a tight chamber. Those relatively rare rifles will usually function better with a small-base die. The overwhelming majority do not (none of mine ever have!).

[MAUSER88]

I'm an RCBS small base sizer die user too. I really don't care about brass life. I'd just rather have them chamber then worry about a case that won't.

[Too Much Coffee]

With the X-die you can adjust the amount of bump to fit your chamber. I use them in .30-06 & .223 Rem. Read and understand the directions with the die. Use the case gage and your rifle to check set-up of die. Size to the point that they chamber without issue. I can reload my cases many times more without trimming and without case fatique from over working/sizing the case.

I have small base dies, I don't use them any more. For cases that have been fired in a MG or very large chamber, they can be used for first sizing.

Try the RCBS X-dies, you will get to like them.

[10X custom guns]

Small based dies were intended to assist in the function of full-autos and picky tight chambered semi-autos with NATO specs. Bolt guns and most commercial AR's, mini's etc. use a SAMMI chamber and do not need the small base to work correctly.