OK. This is from memory but I did rechamber a 24" Winchester from 270 to 270AI, to 270 Gibbs, and then, with enough setback to cleanup the shoulder, to 270 Weatherby. The owner of this rifle used the casehead expansion method of determining excessive pressure (I don't want to hear it) and loaded each to where he saw measurable expansion then backed off to where he saw none. He used Winchester brass for the standard cases and Weatherby brass for the Weatherby. As I recall, the resultant velocities, with 150 Hornady's and 4831, were:
270 Win 2940
270 AI 2990
270 Gibbs 3070
270 Weatherby 3180
He felt the Weatherby could have done better but the brass was soft. Could be.
Right now, I'm having an issue which frequently rears it's ugly head on this site where the typing function keeps failing so I'll say (just happened again) no more. The beneficaries of this are those who hang out here because they don't have to read as much of my stuff. GD
