.223 Bad Neck Tension

[Lee Q. Loader]

How is it possible that I have poor neck tension?
Inside case mouth is .2195 or .2200
Bullet is a Speer 52 grain HP, measures .2240

I could tell right away when I seated a bullet that something wasn't right. I could push the bullet deeper against a 2" x 4" with the palm of my hand.

Brass is all range pickup once fired LC '14. I had to remove primer crimp so I know once fired.

Prior to loading these, I loaded 100 rounds with LC '18 brass and 40 grain Varmageddon. Great neck tension.
I used the same sizing die and never adjusted it between loadings. RCBS .223 small base.

Anyone have any ideas? It's pretty frustrating. I have no answers.

 

[edwardware]

Inside case mouth is .2195 or .2200

How measured? If you're measuring ID with calipers, you'll always be wrong, and there's your problem. If you're using a pin gauge, then we have an interesting problem.

I suggest never attempting to measure small IDs with a caliper, and instead measuring your expander ball instead. I bet the problem lies there.

Also,

Bullet. . . measures .2240

implies that you're in a temperature controlled environment, with a traceable (or at least gauge-checked) high-precision micrometer, and that you've developed or been trained in the hand skills necessary to measure to 0.0001". If you aren't/don't/haven't, then settle for 0.001"; if you're using a caliper, you should be suspicious of that last digit.

This doesn't imply that the caliper is insufficient, just that you shouldn't be led astray be significant digits you aren't actually capable of measuring.

 

[NMexJim]

Ok, so we know it's once-fired because you had to swage. So, no brass ductility problems.

You said you did not readjust your RCBS small base dies. Have you mic'ed the expander ball? It should be couple thou less than the bullet diameter. Is it clean?

As edward mentioned, it's hard to tell anything from your id dims. That's .005 difference in your readings.

Looking at some resized LC I've got, it runs a very consistent .222 ID which is what I'd expect to see - about .002 neck tension between the case mouth and the bullet. I don't crimp at all.

All else fails, tear down your dies and clean them.

 

[NMexJim]

I pulled out my expander ball and it measures .223 FYI.

 

[71GTO]

Lee Q. Loader, You can buy cheap SS pin gauges from Amazon for as little as $4-5 each. Get them in .221, .222, .223 and maybe even .224" and you will know exactly what the ID of the case is before and after sizing. It really helped me to perfect my neck tensions more than any other tool! Good Luck Mate

 

[Kaldor]

How is it possible that I have poor neck tension?
Inside case mouth is .2195 or .2200
Bullet is a Speer 52 grain HP, measures .2240

I could tell right away when I seated a bullet that something wasn't right. I could push the bullet deeper against a 2" x 4" with the palm of my hand.

Brass is all range pickup once fired LC '14. I had to remove primer crimp so I know once fired.

Prior to loading these, I loaded 100 rounds with LC '18 brass and 40 grain Varmageddon. Great neck tension.
I used the same sizing die and never adjusted it between loadings. RCBS .223 small base.

Anyone have any ideas? It's pretty frustrating. I have no answers.

Once fired? Hmm, what size is your expander ball?

 

[Lee Q. Loader]

Thanks for the help everyone. I'll pull the expander and clean it and the entire die. I'm betting that will be the problem.

 

[Trent]

0.004 isn't bad for neck tension but measuring that is tricky as others have noted.

I've had problems with oil / carbon buildup on the expander, cleaning is a good first choice.

On one occasion I had an expander die which was slightly too large on 8x57mm (was only giving me 0.001-0.002 tension depending on springback, way too light). After a lot of measuring to make sure it wasn't my imagination, I chucked it in a lathe and used polishing paper to hone it down a couple thousandths.

Even so if you are lubricating properly during sizing, you may be leaving a very light film of oil inside the case neck. 0.004 tension coupled with a tiny smidge of oil, crimp or no crimp you will be able to set that bullet back by shoving it against a 2x4.

If there's oil residue left on the inside of the case mouth, it's an easy solve, after sizing, q-tips can work good to clean it out.