I think feeling under armed is relative. Some people aren't going to feel safe unless they're behind a Browning 50 cal Machine Gun with a full belt of ammo and 10 ammo boxes in reserve.
I think most things can be described with a bell curve. Self-defense situations can be described with a bell curve too. Are there situations outside of my home where I could find myself facing multiple assailants and 7 rounds before reload won't be enough? Possible but highly unlikely. There are people who live in constant fear that the equivalent of zombie-ocalypse is going to break out any second. And they carry something like a 46 ounce high-capacity 10mm hand cannon with 2 spare magazines, and a pocket BUG, and a 38 snub nose in an ankle holster. And usually when those people make comments on a forum disparaging the 9mm, or the R9, it's because even with all their stuff, they feel unsure and "under-gunned" and feel compelled to comment on anyone who holds a different view.
The R9 is accurate for most self-defense situations. There are very good 9mm bullet designs out there , rounds that will punch a 14" deep, .65" diameter whole in an attacker. It's all I need for the bulk of the bell curve describing most self-defense situations.
I have an HK P7M8 and I love it. It is my nightstand gun, and when we get concealed carry in Illinois I will probably carry the P7M8 quite a bit, but the R9 just slips in a pocket so it will be with me too, and for those situations where the P7M8 would make my shorts fall down without wearing a big belt - I'll probably take the R9.
Incidentally - the small size ends up being useful in all sorts of unexpected ways. I do a lot of bicycling. My R9 in the Nemesis holster fits my Schwinn Bike Bento / Accessory Bag (sits in front of the seat) I don't really have a good solution for taking my P7M8 biking with me.
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