James is right about the 404 Jefferys ,but you cant use the 404
case because of the rim dia.(unless you turn them down, Blow them
out and trim to 2.760.
Most cartriges based on a parent case have the same size case head
Diamenter and are just blown out to increase powder cacapacity.
Remingtion was smart to design there on cases for the RUM,s because
you can use a standard magnum bolt face with any of the RUM,s
The Jefferys has a .537 rim Dia. and a body Dia.of .544
The 330 Dakota is .545 and a body diameter of .545
The RUM,s rim is .534 (rebated)and the body Dia. of .550
And the case capacity is only 2 to 4 grains less than the Edge or the lapua.
J E CUSTOM