LET R' STRIP!!!

As long as it is in good shape I don't see a problem. I'd clean the rifle real good after in case the powder and/or the primer is corrosive.

Look for any tarnishing around the case mouth. That will indicate if the bullet was seated air tight. Also look for any discoloration around the primer pocket. If it's all clean you shouldn't have any trouble with it unless maybe it's over or under pressure. Of course inspect the cases and barrel bore after each shot for any signs of trouble.

I'd keep some stashed away though for collectability or conversion pieces.

As long as ammo is stored in relatively friendly conditions it should have a shelf life of several decades. The oldest I've fired was some old US Government .45 pistol ammo that was head stamped indiacting it was loaded in 1940. I'm assuming it was part of millions of supplies sent over the Britain during Lend Lease. Likely made it's way into storage once off loaded from the ship, there it sat undisturbed for the remainder of the war and later until being discovered in the late '90s. It fired and cycled just fine out of my Colt 1911. I would not however trust ammo this old stored under unknown conditions for self defense or protection. When I was a kid in the early 1980's I sometimes hunted with ammo that my father had loaded back in the1950's, never a problem there.

I guess I'm the downer cause I wouldn't shoot it. I'd leave it for keep sake. Why risk hurting your 375? My 2 cents.

If it's sealed in lead containers, I'd be pretty confident in it. What kills ammo is degradation of metal and propellants -- and the big factors in both are moisture and oxygen. Your ammo has been protected by both, so its rate of degradation would be greatly reduced.

During the late '70s, my Dad inherited a 1911 my grandpa brought back from WWI. I shot a bunch of government issue .45 ACP stamped 1943 and 1953 and it worked great. I also had some .45s stamped 1917 and 1918, but I just couldn't shoot those -- aside from the likelihood of mercury primers, it just didn't seem right. I also inherited several boxes of Peters .20 gauge ammo from the '40s and shot a lot of birds with it.

Now when I think back on that, I feel like a dummy for wasting museum pieces when new ammo was easily available. 1930s vintage .375s still sealed in the tins? That might be worth more than the enjoyment you'd get shooting it.

+1. I'd keep it pretty much that was to. If you hunt anything you need that much gun for, you can afford a new box of ammo.