Interesting 308 die measurements

[waste_knot]

I was measuring some dimensions on a RCBS 15501 FL sizing die in order see what was happening to the brass. The neck bore is 0.307 measured with a gauge pin set. LC brass resized with this die has a neck ID of 0.278. The expander ball measures 0.3065. You can see how much a stock die works the brass as opposed to a neck bushing die. I use a 0.334 bushing with the same brass so the RCBS die is 0.026 smaller at the neck.

 

[ChrisGarrett]

I was measuring some dimensions on a RCBS 15501 FL sizing die in order see what was happening to the brass. The neck bore is 0.307 measured with a gauge pin set. LC brass resized with this die has a neck ID of 0.278. The expander ball measures 0.3065. You can see how much a stock die works the brass as opposed to a neck bushing die. I use a 0.334 bushing with the same brass so the RCBS die is 0.026 smaller at the neck.

You sure that your pin die is correct? A die neck opening of only .307" (OD on the brass even with springback) seems like quite a bit of sizing is going on, if you think about it? What's the OD of your necks after you size them without the expander ball (which seems to be in the ballpark)?

Something seems amiss. I've got standard dies here to go along with my plethora of neck/FL bushing dies, but I don't think that they cinch things that tightly, down.


Chris