noob reloading question
 

so I have my RCBS 2 die AR set for 223, and it appears to me that the expander rod for neck flaring is undersized. The internet says it's happened to other people, and I've triple checked it, I'm positive it's not just me being inexperienced and making a mistake. The rod actually passes through the neck of a sized case, and measures .223 at it's widest point (not very great for flaring a neck for a .224 bullet).

anyhoo, I have sent an email to rcbs customer service, and in the meantime I'm wondering if there's any issue simply chamfering the case necks to seat bullets instead of flaring them? I tried a couple dry (no powder or primers) and had no issues

I'm a bit confused here, flaring is done only for seating cast bullets, I just chamfer my cases for jacketed bullets.
Cat

ok cat, I was under the impression that a slight flare was desirable for seating jacketed bullets as well

What kind of gun are you loading for? Never heard of an AR sizing die, small base? If it's a bolt gun chamber a sized empty brass, if it fits, seat bullet and chamber again, if that works, load and shoot. If it's for a semi auto, size and use a headspace/chamber gauge.
Try seating a bullet in an empty case, Measure the case neck in the same place, before and after seating the bullet will give you a rough idea of your neck tension. More neck tension is better for semi autos, I crimp them all, some people don't. If your not having issues seating the bullet, you should be ok.
It's a good buy for a headspace gauge when reloading for semi autos, I use Wilson. You can check your fired brass and reloads without chambering.

No flaring required for the 223. If the bullet isnt wrecking the brass and can be chambered your fine, chambering or checking the chamber/head space in semi autos is a must.

I believe by "flaring" the OP is describing expanding the whole neck and is concerned with the dimension of the expander ball.

OP: You need the inner dimension of the neck to be smaller than .224 so that you have some tension holding the bullet in the neck.

For me, the Lyman carbide expander was worth it for higher volume 223 reloading. I find I don't have to lube the INSIDE of the necks which speeds things up.

https://www.amazon.ca/Lyman-Expander...+ball+for+RCBS

Ok question 2:

I'm trying to throw 27.5 grains (the starting load for CFE223). The volume of that much powder should be 1.78 CCs according to my manual, but I need about 2.04 CCs (according to my lee powder measure) to get 27.5 grains. I have zeroed my scale several times and am getting the same result consistently. That much powder in a 223 case fills the case to the neck. I have an acquaintance in town who reloads, and at some point he said he'd bring his digital scale over to verify my load before I start putting it into cases.

can anyone suggest what might be going on? I'm fairly certain I'd be overcharging them, but it's the perfect amount according to my scale

It could be nothing more than your particular brand of case not having enough capacity.
case capacity varies from brand to brand, and especially military brass has less capacitor than many civilian cases.
Is it filling to the base of the neck or right up?
if you hold the case with a finger over the case mouth it and tap it on a hard surface you will also find that the powder will settle .
Cat

When I am developing a load I don't use my powder thrower, I use a Lee dipper (or any static free scoop) and trickle it onto the scale. Then I use the powder thrower when I have found my pet load.
Looking at http://www.imrpowder.com (because I don't have my manual in front of me) and they list 26.0gr to 27.8gr with a 55gr bullet. Are you sure 27.5 is the starting load in your manual? What weight if bullet you using?

I have loaded a batch of rounds to the proper OAL with 40grain varmageddons, and when I shake the case there is still room for the powder to move. I've checked and rechecked my scale, and as long as it's accurate then I'm throwing exactly 27.5 grains of powder.

I'll go shoot them out of my single shot tomorrow and see if I blow up.

Wear safety glasses and separate the action from your head/body with a suitable buffer.

For 40gr bullets that should be the starting load. Good that they shake, it's not compressed. Next load 3@ 28.0, 3@ 28.5 and 3@ 29.0gr you should find the sweet spot.