Need Expert Opinion

[K22]

I've been reloading for 40+ years and recently encountered something I've never experienced before. When I size the case the expander ball does not make contact with inside of the neck. The cases were given to me by a friend who has stop reloading. The were Wincheter, new, unfired, about 20 years old. I did my normal case prep, full sized, trimmed, uniformed, deburr flash hole using standard RCBS Full Length Sizing dies (no shoulder set back on first size, .002" on fired cases). This only happens on these cases. With Remington cases I obtain some expansion (drag) of the neck with the expander ball. Here's the data

Cases: Winchester New Unfired
Caliber: 308 Winchester
Expander Ball Diameter: .305"
Sized Neck Diameter: .332"
Neck Diameter w/ Bullet: .335"
Fired Neck Diameter: .345"

This doesn't seem to affect the accuracy, at least to my level of need. The rifle is a Tikka T3 Light, hunting rifle. Groups about .85 which meets my needs for a hunting rifle. Just curious because I've never experience this before.

Would appreciate your opinion / comments.

 

[JohnHenry]

Using your measurements, your neck wall thickness is (.335-.308)/2=.0135. After you size, the inside neck diameter equals .332-(2)(.0135)= .305. You expander ball may be just ever so slightly smaller than the neck ID or just touching the inside of the neck wall so lightly that you can not feel it. You have .003 grip on the bullet which should be fine.

PS: With approximately a .346 neck diameter chamber(assumes .001 spring back of the fired brass), your brass life may be short as you are working your case neck quite a bit having approximately an .011 difference between your loaded round and the chamber neck diameter.

 

[hoz53]

Using your measurements, your neck wall thickness is (.335-.308)/2=.0135. After you size, the inside neck diameter equals .332-(2)(.0135)= .305. You expander ball may be just ever so slightly smaller than the neck ID or just touching the inside of the neck wall so lightly that you can not feel it. You have .003 grip on the bullet which should be fine.

PS: With approximately a .346 neck diameter chamber(assumes .001 spring back of the fired brass), your brass life may be short as you are working your case neck quite a bit having approximately an .011 difference between your loaded round and the chamber neck diameter.

I'd size one without the expander in then measure inside neck Dia. You know the expander dia so that should tell you. The Remington's may have thicker neck walls.