Sizing .223 cases - neck measurements

[TexasShooter59]

Lately, I've been thinking about neck tension, bushings, etc. for rifle reloading. I currently use a set of Lee dies for reloading .223. Out of curiosity, I measured the necks on some cases that had a bullet seated and it was about .249 or .248, somewhere in there (I did not write it down). I resized some cases like usual and measured - .2475-.248. Then, I removed the expander ball and resized some cases - .2395-.240. The expander ball measures .223 at it's widest place.

Any thoughts about all this? I don't have any other .223 dies to compare to and wondered how these numbers compare to others.

On a side note, I thought about loading up the cases sized to .240 necks and comparing the velocity to the others just for fun, but was not sure if it would cause a pressure situation and be unsafe. Is it safe?

 

[W.E.G.]

Rifle brass is nothing but a ductile gasket that seals the burning propellant during ignition.

How much additional pressure do you think you can achieve by what amounts to essentially a slightly tighter than normal crimp?

I think you will deform the bullet jacket and destroy accuracy long before you could ever get enough neck tension to raise pressures enough to even consider.

Somebody will be along shortly to extol the wonders of the Lee Factory Crimp Die as to how it "improves accuracy."

 

[helotaxi]

It would be safe, but a royal pain to seat the bullets. Flat based bullets would be right out.

The primary problem that you run into when only using a bushing to size the neck and not running an expander is that every brand of bras has a different neck thickness. To get consistent neck tension you either have to only run one brand of brass, change bushings for each brand of case or neck turn/ream every case to get them all consistent. The reality is that the outside diameter of the neck doesn't tell you that much if you don't know the thickness of the brass. Neither mean much if that thickness isn't consistent. Some brands are more consistent than others but they all have some variance. Since ultimately the inside neck dimension is what matters, running an expander ball through the necks gives you the most consistent neck tension regardless of case and with the least amount of work.

 

[TexasShooter59]

How much additional pressure do you think you can achieve by what amounts to essentially a slightly tighter than normal crimp?

Right there is exactly why I asked if it's safe! I'd bet the initial pressure curve changes, but I have no idea at this point in my learning just how much. I'll load 'em up and see what happens.

(Imagine that, no one has come along and talked about the Lee FCD!)

Thanks for your reply!

 

[TexasShooter59]

The reality is that the outside diameter of the neck doesn't tell you that much if you don't know the thickness of the brass. Neither mean much if that thickness isn't consistent. Some brands are more consistent than others but they all have some variance.

Thank you for your response, helo. One thing I have learned is not to get too uptight about a couple thousandths variance. Especially since I'm not doing Benchrest!

 

[243winxb]

Using RCBS Standard FL dies

223 Rem. Reloaded neck diameter of FC brass .246" to .2475" Two different lots. Factory Federal ammo XM193F is .248" RCBS expander ball is .222" Have some neck turned BHM at .244" to .2455" loaded using standard die. Even turned necks will change wall thickness after a few loadings, with or without an expander. My 243 brass using bushing die, no expander, 18 loading, wall thickness has changed. Factory chambers let the brass be worked a LOT.

 

[TexasShooter59]

The numbers I mentioned in the opening post were with FC brass. Interesting that the RCBS expander ball is .001 smaller than Lee. My Lee, anyway.