Would I regret getting a 9mm instead of a 40 S@W or 45ACP?
I’d say no-over the years I’ve tended to move down in caliber as the quality of SD ammo and magazine capacity has increased. My last CC purchase was an XDSC9 (was carrying XDSC40). My early model XDSC40 held 1 more round than the XDSC9 (I’d rather have 9 rds of 40 than 10 rds of 9mm), but since they changed the mags on the 9 (upped the capacity by 3 rds), I’ve gone from the 40 to the 9. Capacity was a partial reason-the 40 (‘specially in a sub-compact) tended to have a bit of muzzle flip, the 9mm much less so-makes for easier double-taps etc.
And before anybody gives you the false argument ‘bout “I’d rather hit ‘em with a 40 or 45 than miss with a lot of 9mm”, I don’t plan on missing with either caliber, but those extra rounds could come in handy!
Convential wisdom says 40 tends to "snap", 45 to "push"-I'd have to concur. Should you go the "4" route, you might consider such-many folks prefer the push of the 45 to the snap of the 40.
What are the different 9mms?
You’ll get tons of answers on this one-I tell a lot of new owners rather than try to sort out the myriad of choices, focus on a highly rated one (doesn’t mean you have to buy it), then when you go shopping, ask yourself why you should buy the particular model you’re looking at over your baseline?
I just helped a newbie go from an LCP to an XDSC9-didn’t tell him to buy it, just showed him the features and told him to use it as a baseline when shopping-he ended up with the XDSC9. Only “bad” thing I can see for the XDSC line is they are tending to get a little thick for CC, ‘specially when compared to Kahr etc.
He chose 9mm for controllability, ammo prices, and he wanted something his wife could shoot without being intimidated.
What ammo/bullets for SD?
Again, you’ll get a variety of answers-don’t know that there’s a whole lot of difference between most name brand SD ammo? In my neck o’ the woods, it’s easier/cheaper to find Gold Dots, usually at police supply stores, some of which sell 50 rd boxes for what many are selling 20 to 25 rd SD boxes for. You might check out Ammunition To Go online for some comparison pricing-a group of locals went together and got enough from ‘em to split shipping costs, but I’ve since found a local store with similar prices.