Smokey262
11-24-2010, 11:00 PM
For a 243 Winchester my understanding is that the SAAMI cartridge size spec is 1.627"-1.634", and the chamber size spec is 1.630"-1.640".
My Forster headspace go gauge is marked 1.630", yet measures 1.622" to the 0.400" datum
A new factory Federal cartridge measures 1.622" to the datum
Why the disparity? How would a max spec cartridge fit into a min spec chamber? Why does the go gauge measure less than what it is stamped, and it is less than the min chamber spec?
My Forster headspace go gauge is marked 1.630", yet measures 1.622" to the 0.400" datum
A new factory Federal cartridge measures 1.622" to the datum
Why the disparity? How would a max spec cartridge fit into a min spec chamber? Why does the go gauge measure less than what it is stamped, and it is less than the min chamber spec?