40-65: Learning what I can

[Kurt]

John.
The .435 is the case neck chamber wall diameter that is a 1/2" long in front of the body taper. That .435 is pretty generous. That leaves about .005" extra room for a .010" case wall thickness using a .410" diameter bullet. in other words that un sized case will hold a .415" diameter bullet. My feeling that is pretty loose for a .408-.410" diameter GG bullet. That leaves a bunch of room for the base of that bullet to expand and then gets swaged back down again to fit the throat.
That is a 12 degree 45 minute zero second. That is just slightly over 12-1/2 degree transition.
Then the next measurement- 2.045 to 2.1002 is how long the 12-1/2 degree is.
The 410 is the free bore diameter. The 2.1002 to 2.2002 is the length of the free bore.
The 1*-30-0 is the pitch of the lead angle on the lands.