[supercat]

I would guess the Savage .32 auto was the first with a double column mag. It was a 10 shot.

Well, unless Savage came up with their .32 in or before 1896 it wasn't the first pistol to use a double-column magazine (though it could be the first to put it in the grip--I don't know).

[yarddog]

I guess there were probably several pistols before the Savage with enbloc magazines which were double column.

Of course I was speaking of detachable ones.