Folks tend to forget that models like the 1917 were used almost exclusively with jacketed bullets, and semiautos were always fed jacketed bullets from the late 1800's on. Yes, copper has a somewhat higher coefficient of friction than lead, but at the velocities and pressures of rounds like the .32 Long the difference in barrel wear rates is virtually nil. Besides, you're not very likely to find many jacketed rounds available for the .32 long unless you handload. If you do handload, just keep the loads within normal specs for the cartridge and no harm will result.

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Pisgah