chamber reaming

Can anyone get me any info, or point me to a reliable source on what the actual chamber pressure was in the small ring Mausers? I’ve got one chambered in 250-3000, I’m assuming I’ll be ok if it was 45k or under. I’ve found wildly varying numbers recommended and in various sources about the...

can anyone recommend a good smith for a chamber reaming, that is cheap and fast turnaround? I want to open them up to a .451 and currently a .449 if its to specs. the groove is exactly the same but im looking to increase pressure/ velocity by way of resistance (maybe im over simplifying but...