Barrel profiles

Has anyone else run their measuring gear over P-14 and M-17 barrels to see what the differences are? (Apart from the obvious breech end ones)

It seems that M-17 barrels have an extra taper added from about 7.25" from the shoulder back to the radius in front of the Knox form.

This may be to give a bit more support to the longer and slightly higher pressure .30-06 cartridge.

Apart from that, the Knox form appears to be the same but the threaded shank is a longer, giving marginally better barrel support.

The coned breech seems to fit with the idea of better feed.

What is interesting, also, is that the P-14 extractor slot is a lot narrower than that on the M-17, which is more Mauser-like. I wonder if the small extractor "footprint" was a result of the original British design. Help from P-13 owners would be handy. Was the idea to maximise support for the highly-stressed .276 case?

BTW, I recently found that Ruger M77 extractors are VERY close in critical dimensions to the M-17. Did old Bill spend some time with the Remington Model 30? I guess, at a pinch, one could be "adjusted" to work in a P-14