It's amazing to me that of the 800 or so Magnum 10 NIDs made before WW2, most it seems are still alive and doing their thing. I have 500606 and shoot it regularly at ducks and geese mostly with Sherman Bells 2 7/8 oz Bismuth loads, or with 12 ga target loads and gauge mates. It makes a hell of a trap gun for Chinese Trap. Mine is in high condition for now and came to me with a box of paper Remington 2s, it might be my favorite gun.