ON TARGET: 30 NOSLER IS NOT BASED ON .404 JEFFERY

In the October 2016 issue of American Hunter, page 94, Ron Spomer, Field Editor, states that the 30 Nosler is based on the .404 Jeffery case.

I must emphatically state that the 30 Nosler is NOT based on the .404 Jeffery case.  It is based on the .300 RUM case.

.404 Norma and RWS cases measure .5405 at the head.  Rem. .300 Rum cases measure .5455 at the head.  They are different cases entirely because of this.  Furthermore, chambers for the .404 measure .545, the .300 RUM measure .550.  So you see, a RUM case won’t fit in a .404 chamber as it is .545 at the rear of the chamber at the same position on the head diameter.  Nosler cases measure .5457 head.

I am a Master Rifle builder with 50 years of experience, of which 33 years is experience building .404 Jeffery based rifles.

Many years ago someone tried to use 30-06 cases formed to 6.5×55.  There is a difference of .006 to .007 thousands. Information came out not to use 30-06 cases, but only 6.5×55 cases.  Given the information misstated in the article, would you writers say the 6.5×55 is based on the 06 case?

It seems someone inexperienced, as so many writers seem to be, measured an expanded to fit the chamber case at the expansion ring to come up with the .300 RUM cases to .5455 at the head and said it was based on the .5405 Jeffery case.

This error comes from lacking technical understanding of the differences from a diameter standpoint, or a case, chamber aspect dimensionally.

We appear to be at a point in history where few have a technical knowledge or the experience to grasp the subject material, as has consistently been the case here. Unfortunately the error, once written about, seems to be repeated and then, like many misconceptions becomes to be believed as truth.

©Randy Selby 9-19-2016