7.62x39 anybody tried this?

[PJgunner]

OK guys, I'll fess up. I have this old geezer (79 years old) friend and the data is for him. I told him he was on a fool's errand but he knows better. I've been printing out the comments here and from the other sites I've asked the question on, and believe or not, he still doesn't get it.
The rifle BTW is am old 1889 Mauser that's been rebarrel to 7.62x39 with a .308" bore. Me? I'd almost be afraid to shoot hat old relic, but he shoots it all the time. I stay away from the range when he's out there with that thing.
Paul B.