First 243 AI Shilen barrel

[mj2evans]

Please help a rookie! I just received a Shilen Savage replacement barrel in 243AI 8 twist barrel. Barrel says 243 AI SS 8T S7. Since this will be my first attempt at fire forming I sized some range pick up Win 243 brass in a Lyman FL 243 sizer. The brass WILL NOT drop into a the chamber,barrel not on gun). The amount that will not chamber looked to be about the length of the neck. I then removed the expander and sized again - these cases now drop right in. As a test I seated an 85g bullet in an empty case to Sierra's recommended COAL 2.650' and placed the round in the chamber. The round stops short of going all the way. I measured the loaded round neck at .273 in. Now that I reread the Shilen site it shows 243AI at .270 in. Does this mean I need to turn my brass? If so how much under .270in should my neck be on a loaded round? Thanks for any feedback.

 

[expiper]

The loaded round shuld measure aprox .002-.003 smaller than the neck dia...sooo .270 minus .003=.267,loaded round neck dia.) minus .243 = .024 divied by two = .012' ...that shuld be your neck wall thickness...Roger