Nonsensical Headspace Measurements on 223rem cases...??

[markm]

Why is that, markm?

Clean brass is so much nicer and neater to deal with. Your hands, dies, machines, etc. all stay cleaner. I decap with latex gloves and that's the only time I deal with dirty brass.

Also, what would y'all (markm, anyone) say is the least amount of steps/work/processing that can be gotten away with for loading just "FMJ basic ammo"?

Rifle is always a little more trouble than pistol due to the case lube removal. For me: decap, clean, lube/size/necksize, tumble off lube, prime, and load.

I could skip trimming on blaster ammo due to no expander ball, but I run all of mine in the Giraud because it chamfers the neck even if nothing gets trimmed.

[bigedp51]

I don't run any lube for neck expansion since it's on the down stroke. If I felt any sort of resistance on the press I would probably lube, but I don't thinks it's been a problem.

Some reloaders use a expander die on the up stroke of the ram to reduce neck runout. On the down stroke if the case has any extractor dings in the rim it can cause the case to tilt in the shell holder.

Does a progressive press change these dynamics? I do not understand why no lube on the down stroke especially with wet tumbled brass. I do not own or ever used a progressive so forgive my questions.

I use a Rockchucker press and Forster benchrest dies with their high mounted floating expander and lube my case necks. The neck of the case is held and centered in the neck of the die when the expander enters the case neck. And on the down stroke of the ram the expander can not pull you necks off center inducing runout.

[Bill Murray]

As a new rifle reloader, I have already learned a lot by reading this discussion. Thanks everyone.

Markm, I have a question about the type of neck expander die you mentioned in Post #14.

I think it's just an RCBS .223 neck expander die. Every time I've forgotten the exact die, the subject comes back up.

Is this the type of die that you are referring to?

https://www.midwayusa.com/product/10...expander-m-die

Or this?

https://www.midwayusa.com/product/73...pander-die-224

So far, I have been using a full length (not small base) sizing die. To help reduce expander ball friction, I have been lubricating the inside of the neck with a Q-tip using the same lube that I use for the case (Imperial Sizing Wax). But your suggestion for using the expander type die intrigues me as a way to reduce the cold working of the case neck.

[bigedp51]

If you want a good neck expander die then get the Lyman type "M" expander, you will have .003 neck tension or bullet grip. And bumping the case mouth on to the .226 step of the expander insures straight inline bullet seating.

[Bimmer]

As a new rifle reloader, I have already learned a lot by reading this discussion. Thanks everyone.

Me, too.

It's threads like this that keep me coming back here.

[markm]

As a new rifle reloader, I have already learned a lot by reading this discussion. Thanks everyone.

Markm, I have a question about the type of neck expander die you mentioned in Post #14.

I have the second one. I have not tried the M die. The RCBS works for me well enough that I've not looked at other options.

[terraMODA]

When you take a balloon and squeeze it, it grows in length. Same with brass. The sizing die squeezes the brass back down so it grows IF you don’t have it adjusted to bump the shoulder back. I see this a lot when I’m setting up my full sizing die. The headspace grows until you screw the die down a little more to achieve the proper shoulder set back. Same with the seating die. If it’s screwed in too much, it can bump the neck back when seating a bullet.

[markm]

The sizing die squeezes the brass back down so it grows IF you don’t have it adjusted to bump the shoulder back.

Interesting. I've never noticed this, but I never move my sizing die. How much length increase have you seen.

That could partially explain why XM193 brass requires SO MUCH trimming after firing the factory load. It's blown out so much that squeezing it down lengthens it perhaps.

[bigedp51]

The amount of upward brass flow in the die depends on the size of the chamber and the size of the die. Meaning the more the case is squeezed down in diameter in the die the longer the case will grow.
Example a small base die would squeeze the case down more before the die pushed the case shoulder back down.



Before I had gauges I would start with a .010 feeler gauge between the die and shell holder and work down until the case chamber freely.

[twadsw01]

I just got a case gauge (Dillon) and am mucking around with some once fired and some prepped cases in it.

How on earth are y'all telling whether or not the cases are above or below the min/max headspace? It is SO close.

I can kind of tell, but it is by no means obvious, whether or not the case is in spec or not.

Also, the case mouth is shorter than the min; is this bad?