Thank for the information Bob.
The question or concern is/raises... From what I just read above the 38-55 concerning brass and Winchester's lacking in advancing the caliber.... I'm trying to figure, and get a chamber measurement, out as to whether this particular rifle requires the 30-30, 2.08 inch brass or the 2.125 brass to obtain the most accurate load for this cartridge.
Accordingly to what I just read regarding the brass, I hope you perhaps can/will elaborate on, is that the thinner wall, at the neck, will allow the use of bore diameter correct bullets and black powder paper patch bullets to be equal or provide better accuracy vs smaller .010 - (guesstimated .015) original bullet diameter loaded, when a paper patch was added that made these cartridges more accurate than gas check bore size bullets.
Brass length, an all together history lesson, in short....had the brass been lengthen to proper size, ie. 2.125, and that the bullet diameter and bore were of equal size, the 38-55 would be more popular than the 30-30 aka 30 W.C.F. of the time/era.
It was so stated that the thicker neck wall brass created accuracy problems by not allowing bore diameter and gas check diameter bullets to properly engage the rifling.