It's my opinion - that capacity is the most overrated issue in selecting a carry weapon.../ and capacity is often used as a crutch, vs learning how to shoot, how to reload, etc...
I live in a large metropolitan area...and there are shootings most every day somewhere in the metroplex...but rarely, even annually, in the areas that I frequent.
I'm very comfortable carrying a 1911 ( 8 + 1 rds in .45 acp / 10 + 1 rds in 9mm) or most any single stack semi-auto ( sig 239 as an example - 7 +1 in .40 S&W or 8 +1 in 9mm ) or a 6 shot revolver in .357 Mag...(so call it 6 - 11 rounds that I carry ) ...and while I do carry a mag for reloading...in my view, its because the single biggest potential for a problem with a semi-auto is "mag failure".../ so the extra mag is there, just in case...and it has extra rounds in it of course...
But I think the statistics are right ...in all probability it will be over in a few seconds with a max of 4 or 5 rounds fired ....
But to improve my odds... I practice 2 - 3 times a week... Draw to 1 shot in 2.0 Sec / Draw to 3 shots in 3 sec - speed reloads, tactical reloads....and at ranges of between 3 yds to 10 yds. I'm older and slower than I used to be, but its my opinion that I can probably remove myself from the situation if the threat is beyond 10 yds...but I can still engage within 10 yds if necessary.
Carry the gun - and the platform and caliber - you shoot the best ...but the point is, practice with it ! ...and it will minimize the issue of capacity in my view...
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I saw, read or heard an instructor somewhere had a drill ...with your carry gun, draw from concealment - target is a full sized silhouette ( and primary target zone is nipple to nipple and a rectangle down to about belly button ( or 8 1/2" X 11" - to mark "the Tactical" center mass area ... ). At 3 yds Draw and fire 1 round in under 2.7 sec / at 5 yds draw and fire 1 in under 2.7 sec / at 7 yds same thing < 2.7 sec / at 8 Yds draw and Fire 2 rounds in under 2.7 sec. ( 5 shots, 5 points if you hit that rectangle...)...and the author's point essentially was, if you can't execute that drill, put the gun away ( until you can do it - by practicing ) ....and carry a cell phone...
and I see a lot of guys, at my local range, week in and week out --- that carry guns -- and they have no chance of passing that drill. But if they were to practice, work on their fundamentals, read, study their weaknesses - and work at it.... I think they would be able to run that drill at 100%.