The 6906 Hi caps are 12+1. It will also accept the 59xx series 15+1 mags but they hang out the bottom a bit. I just shot my new (used but new to me) 6906 today and it posted 12 rounds into 4 inches at 25 yards. My 3913 (also new to me) posted 2.5 inches at 25 yards. This was my first time shooting either gun since they were both purchased in the last week and a half. I am seriously impressed with both. No problems of any kind and mind boggling accuracy. Especially for the 6906 which is an ex LEO gun and very very used. I will be sending it out to be refinished since it has WAY too much "character" for my liking
There is an after-market fix for the 15 round mag in the S&W 6906. It is a filler, so to speak, to blend the 15 rounder into the shape of the grip. I will send photo if there is any interest.
presspics is right... the 6906's original magazine is a 12-rounder... but the 15-round mags from the 59xx series S&W's work as well. The stick out a bit though.
Brownells, sells the filler for the 15 rounder to fit the 69xx
Works real well with mine. the filler is called the "2+" and was intended to use with the .40 cal S&W'S.
Why have just 12 when you can have 15?