.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

[Parabuteo]

You do not need a canelure to crimp unless it is a roll crimp. We crimp match bullets for use in AR15s regularly which improves consistency. Lee are quite clear on thsi in their instructions that you do not need a canelured bullet.

That said IF the bullet has a canelure, I will adjust the die to crim into it.

[Thegreg]

You do not need a canelure to crimp unless it is a roll crimp. We crimp match bullets for use in AR15s regularly which improves consistency. Lee are quite clear on thsi in their instructions that you do not need a canelured bullet.

That said IF the bullet has a canelure, I will adjust the die to crim into it.

I have a Lee factory crimp for the .223. I did some experiments with it and personally found no advantage accuracy-wise to crimping. It's an extra step and puts more stress into the brass. I've heard that it improves reliability cycling through rifles like the AR15, but that's not an issue with the type of rifle I have.

New expander button is on it's way, will update with results!

Cheers
Greg

[Parabuteo]

I have a Lee factory crimp for the .223. I did some experiments with it and personally found no advantage accuracy-wise to crimping. It's an extra step and puts more stress into the brass. I've heard that it improves reliability cycling through rifles like the AR15, but that's not an issue with the type of rifle I have.

New expander button is on it's way, will update with results!

Cheers
Greg

Its chief advantage is to dummy the loading into the landes effect. By loading into the landes the peak let off pressure is usually more consistant. Obviously if you are loading for a magazine length you dont get the ability as a rule.

This is proven, and I have seen the proof over all the rifles I have used when loaded to mag length. There is a science behind it. Clearly back when I was loading for F Class we did not have to worry about it, and I managed a 6fps ES on my load eventually (measured independantly be several chronos). Thank god I am out of that one

It produces next to no extra stress in the brass as it is right at the very end of the neck. It really only increases reliability where you have semi or full auto capability.

Another consideration may be a collet sizer which will produce a much better more consistant neck, but again it's Lee I use Lee in a Forster press, along side RCBS, Redding, Wilson and Forster dies and they all work well. True, you need to know what you are doing with the Lee dies and they need lubrication (of the collet and cone faces etc) but they work well

[Thegreg]

Another consideration may be a collet sizer which will produce a much better more consistant neck, but again it's Lee I use Lee in a Forster press, along side RCBS, Redding, Wilson and Forster dies and they all work well. True, you need to know what you are doing with the Lee dies and they need lubrication (of the collet and cone faces etc) but they work well

If the new expander button doesn't cure the problem I'll look at getting a collet die set, or possibly an expander mandrel. I use the Lee collet die set in my .375 H&H and it does work very well. I might end up getting one for the .223 too!

Cheers
Greg

[pothunter]

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

It does seem a bit undersize, on various dies that I have had the expander has varied between .221 to .223, apart from Lee collet dies which had a .220 mandrel as they are squishing the neck onto a mandrel rather than using an expander to push a neck out that has already been undersized by the die.
Too much neck tension is usually avoided, but..., if the ammunition that you are making gives good accuracy with that degree of tension, I would probably take a little material off the trimmer pilot so that it fits the neck.

Many knock Lee stuff but I have been quite happy with the results from collet neck sizing dies.

[Thegreg]

It does seem a bit undersize, on various dies that I have had the expander has varied between .221 to .223, apart from Lee collet dies which had a .220 mandrel as they are squishing the neck onto a mandrel rather than using an expander to push a neck out that has already been undersized by the die.
Too much neck tension is usually avoided, but..., if the ammunition that you are making gives good accuracy with that degree of tension, I would probably take a little material off the trimmer pilot so that it fits the neck.

Many knock Lee stuff but I have been quite happy with the results from collet neck sizing dies.

Thanks for the reply. The sizes you have quoted sound right to me. I think it'd be way too much neck tension if it were left as it is. I've changed to this die set from one I was borrowing so it's the die set that's the issue, I'm convinced of it. I know it'd be easy to polish the pilot down a bit but I didn't have this problem before and would rather leave things as standard.

I think I'll get a Lee collet die set for what they cost. Once I've fired the fully sized brass I'll neck size using the Lee and see how they do.

Cheers
Greg

[Parabuteo]

If the new expander button doesn't cure the problem I'll look at getting a collet die set, or possibly an expander mandrel. I use the Lee collet die set in my .375 H&H and it does work very well. I might end up getting one for the .223 too!

Cheers
Greg

As you know G, you get a perfectly parallel neck. I used a wilson mandrel with my .308 for a while but then went over to Lee collet and Crimp. Obvioulsy as you say the crimp is not essential but helps in some cases wheer you are stick at mag length. With the .308 I was shaving tiny slivers of copper off of the bullets. Both solutions cured it but it made sense to remove a process.

I only use a button when FL resizing, apart from the 556 after the initial FL most of the time it is then neck only. I FL resize the 556 purely because they need to chamber 100% and quickly, then they get the collet so yes they may get over worked a bit but they tend to get used 5 times and then re-annealed and bunged into practice/SR loads (100 yards for standing etc).

The trick with these dies is to lube the cones so they dont stick, some suggest polishing them. I think it makes a difference what press you use as well. The forster floats and allows the dies to self centre which seems to work well with Lee (or any dies I have used).

Good luck with it anyway matey.

[Thegreg]

Sorted! New expander button arrived today. Measured .2225" opposed to the .220" of the old button.

Ran a case through and the internal neck diameter is now .2215", and is a perfect fit over the trimmer pilot.

Thanks for all the replies guys, all the advice is much appreciated. Will probably get a Lee collet die anyway, just to try out!

Cheers
Greg

[Parabuteo]

Sorted! New expander button arrived today. Measured .2225" opposed to the .220" of the old button.

Ran a case through and the internal neck diameter is now .2215", and is a perfect fit over the trimmer pilot.

Thanks for all the replies guys, all the advice is much appreciated. Will probably get a Lee collet die anyway, just to try out!

Cheers
Greg

Cheap as chips. Glad its fixed