.223 case mouth size?

[Thegreg]

I've just FL sized a load of .223 brass using RCBS dies (which aren't new) and come to trim them the case mouths wont fit over the pilot.

The pilot measures .220", as it's supposed to. my case mouths are measuring .218-.219", so no wonder they won't fit over the pilot!

Would someone mind measuring the case mouth internal diameter of a sized .223 case please? I would have thought it should be about .222"?

Unless anyone knows any different the conclusion I've come to is the expander ball in the die is worn out, does this sound feasible?

This is the first time I've used this die set which I was given off a friend, and looking at some of the old brass that this die set has done, they're tight too.

Might see if I can get a new expander/decapping pin holder and run them through again.

Cheers
Greg

[miroku6.5]

Hi
My 222 brass
Measurement internal Neck dia after sizing =.222 so about two tho NK tension
So think your right on the expander ball
👍

[sarge4318]

If it is consistent and you've not been getting any trouble leave it alone.

Do you neck crimp?

[Thegreg]

Hi
My 222 brass
Measurement internal Neck dia after sizing =.222 so about two tho NK tension
So think your right on the expander ball
👍

Thanks, I'd have expected about .002" neck tension. Thing is I've gone and ran ALL my brass through these dies so didn't have an old sized case to check and compare.

If it is consistent and you've not been getting any trouble leave it alone.

Do you neck crimp?

I can't leave it alone, if the necks are too tight and won't fit on the case trimmer they're not much good!

I don't crimp unless there's a cannelure, and that's pretty rare, so no I don't.

Cheers
Greg

[pothunter]

Have you measured the expander ball?

[Thegreg]

Have you measured the expander ball?

Measures .220" which must be undersize surely. I'd expect this to measure about .223" to allow the brass to contract back down to .222". I don't have another one to check and compare but will order a new expander tomorrow anyway.

Cheers
Greg