[quote]All fired case, factory and reloaded do not appear to measure consistently round, they're a bit egged and I searched for the largest measurement to report.
Both Winchester and Marlin lever-action rifles are reamed "eggshape" at the rear of the chamber to facilitate chambering. Every rifle from both mnufacturers that I have looked at were similar.
I too always use the largest reading. It is quick to rotate the case in one eigth turns measuring as you go to get the high reading.
If you are using the factory round bead I find these difficult to shoot well with side light. In the afternoon with soft light at your back they will show up well.
You have hunting accuracy but it will build your confidence in your rifle to shoot from the bench and "proove" the accuracy of your loads.
I assume your cases in the new unfired condition are about .4145" ?
Your measurements do not "alarm" me. I regularly see .4199" with 200 grain jacketed bullets in the .375 cases and published maximum loads. I'll post a link to a thread on the Beartooth forum from when I was comparing .38-55 brass to .375 Winchester brass with the same loads. I was reading a lot of brass substitution threads at that time and wondering what all the fuss was about. I did not experience any loose primer pockets or other visual indications of high pressure when shooting .375 Winchester load data in old R-P .38-55 cases.
About the Gun Digest, I meant to say your local Library might have it. If it does not go to the help desk and ask about an Inter-Library loan. Our Inter-Library loan system works great and has given me access to many books I could not hope to see otherwise.
I know you are setting up to be a "one load" guy but if you get the chance do not overlook Hodgdon Benchmark in the .38-55. I use it in the .375 and my father uses it with excellent results in his .38-55's.
Benchmark has one small drawback in the straight wall cases. It will sometimes leave a few very hard unburned kernals of powder in the chamber and these will put small dents in the next fired case. I have had very uniform results with Benchmark and 255 grain bullets in the .375 Winchester. When graphing loads for fps per grain of powder Benchmark seems to act a little more like an extruded powder than a ball powder in that the graph does not "break over" as you reach a maximum load level.
While I dont shoot a .38-55 it is an interesting cartridge and I'll enjoy reading about your load trials.
Edit] Dave, here is a link to a thread at Beartooh. You may want to jump to the second page about halfway down. I compared a few .38-55 cases to the .375 case. There is another longer thread on the same subject but it has escaped me for the moment.
Remeber I have no experience with hot .38-55 loads, I was just taking a look for myself at what some others were reporting at the time.http://shootersforum.com/showthread...p;amp;pp=15&highlight=.375+loads