So, you found that it was a 1.000"x16 tpi V-thread on all of them and the Ruger No. 1 barrel will be pretty easy to get fitted to the M77 Hawkeye ?
Trim off the extractor cut on the breech end of the Ruger No. 1 that has 0.875" length of engagement,
and it will fit perfectly timed into the Hawkeye,
which has what length of thread engagement in the receiver please ?

Ron aka "Rip" for Riflecrank Internationale Permanente
NRA Life Benefactor and Beneficiary
.458 Winchester Magnum, Magnanimous in Victory
THE WALKING DEAD does so remind me of Democrap voters. Donkeypox.