Author: britrifles
Subject: Case Neck Concentricity
Posted: June 20 2023 at 12:14pm
Yes, I have polished the expander on the FL die.
Subject: Case Neck Concentricity
Posted: June 20 2023 at 12:14pm
Yes, I have polished the expander on the FL die.
I use a spray on lube that I make from Isopropyl Alcohol and liquid lanolin. I set up the cases in a loading block and spray them such that the insides of the neck get lube as well.
I've also tried a separate application of sizing wax to the inside of the neck with a Q-Tip, didn't make any difference in resulting neck concentricity. I might try dry lube next.
I do think that it's the neck expanding where things can go wrong and pull the neck out of alignment. This is one of the advantages of a bushing sizer, no neck expanding after its run into the die.
Shamu, have you checked your cases for run-out? If so, what do you typically get? After I wrote the last post, I FL sized another 50 cases, these were S&B. I could feel significantly less resistance to withdraw the cases from the die (the Lapua case necks are substantially stiffer than the S&B). All but one of those 50 cases measured neck concentricities of less than 0.002 inches.