optimum neck dia. for a given CB dia.

[JBMauser]

Gentleman, in your years of tests and loads have you found a optimum neck size for a given cb dia. My question would relate to say which spud dia. on an "M" die. If I have a bullet that drops at 3.15 and I am going to stuff into a .303 or 7.65 Argi. broove dia. of .311 and .312. what is the best inside dia of the resized neck. I have just gotten a herter's universal resizing die that has an 8mm collar which takes the neck down to .312. I plan on just belling the mouth and loading them up. I think .02 under bullet size should be good for neck tension. what say the group. for .30 cal I now use the resizing mandrel from my .303 die. in the .30 cal dies. It has helped accuracy. jb

[Bass Ackward]

Gentleman, in your years of tests and loads have you found a optimum neck size for a given cb dia. My question would relate to say which spud dia. on an "M" die. If I have a bullet that drops at 3.15 and I am going to stuff into a .303 or 7.65 Argi. broove dia. of .311 and .312. what is the best inside dia of the resized neck. I have just gotten a herter's universal resizing die that has an 8mm collar which takes the neck down to .312. I plan on just belling the mouth and loading them up. I think .02 under bullet size should be good for neck tension. what say the group. for .30 cal I now use the resizing mandrel from my .303 die. in the .30 cal dies. It has helped accuracy. jb

jb,

For straight cases, tight enough is right up until it starts to size my bullet. So hardness affects that guestimate. My expander on my 44 is .410.

On bottle necked cases, I ream all my cases for .002 if I am not crimping. But I gt ignition from a light engraving upon chambering. If I had to jump, I would have no heatburn about increasing this too.