https://saami.org/wp-content/uploads/2018/01/Z299-1_ANSI-SAAMI_Rimfire.pdf

[Linked Image]

[Linked Image]

Looks like the 17HMR is bigger everywhere than the 17M2. So everything inside the chamber looks ok.

Check that there is room to get the long cartridge in and out of the the chamber.
I had to make an ejector over ride button in a Mosin Nagant to shoot the longer 300WinMag. Unfired rounds were too long to eject..

There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. -Ernest Hemingway
The man who makes no mistakes does not usually make anything.-- Edward John Phelps