What Is the Best Caliber for Everyday Carry?
A student in one of my Boynton Beach classes asked me last month if his .380 was “good enough” now that he’d decided to carry daily instead of keeping it in a nightstand. That question comes up almost every class, and the honest answer disappoints people looking for a simple ranking. The best caliber for everyday carry is the one you can shoot accurately, carry consistently, and reload without hesitation under stress, and for most adults in South Florida that turns out to be 9mm, though .380 ACP and .45 ACP both have real, defensible uses depending on the person.
What the FBI Actually Tests For
Law enforcement agencies settled decades ago on a penetration standard rather than a caliber preference. The FBI’s ballistic protocol calls for defensive ammunition to penetrate 12 to 18 inches in gelatin after passing through four layers of heavy clothing, a range built around getting through winter coats and reaching deep enough to stop a threat without blowing straight through a target and endangering whoever’s standing behind them (Hornady’s summary of the FBI protocol). That standard applies regardless of caliber. A well-designed 9mm load and a well-designed .45 ACP load can both land in that window; a poorly designed load in either caliber can fail it.
Independent testing backs this up. Lucky Gunner’s ballistics lab ran self-defense loads through synthetic gelatin behind a four-layer fabric barrier and found some 9mm rounds over-penetrated past 18 inches after clogging in heavy clothing, while a few fragmenting loads actually fell short of the 12-inch minimum (Lucky Gunner Labs testing). Their .380 ACP results told a similar story: a Federal 99 gr HST round penetrated 22.48 inches with a 0.354-inch expanded diameter, while a Barnes 80 gr TAC-XP only reached 8.64 inches but expanded to 0.452 inches. Neither number alone tells you which is the better carry round. Ammunition selection matters as much as caliber selection, maybe more.
Why 9mm Wins the Recommendation for Most People
Here’s my actual position, not a hedge: for the majority of adults starting out, 9mm is the right default. Modern 9mm defensive loads meet the FBI penetration window reliably, magazine capacity typically runs higher than comparable .380 or .45 platforms in a similarly sized gun, and recoil is manageable enough that a nervous first-time carrier can still put rounds where they’re aimed under stress. I’ve watched too many students buy a .45 because it “hits harder,” then flinch through their first range session and group shots two feet low. A round you can’t place accurately doesn’t hit harder than anything.
.380 ACP still has a place, mostly for smaller-framed shooters, weaker grip strength, or genuinely difficult concealment situations where a subcompact .380 disappears under summer clothing better than a 9mm equivalent. The tradeoff is real: smaller cartridges generally mean less margin for error in bullet design, which the Lucky Gunner data shows plainly in how much variance exists between .380 loads. If you carry .380, spend the extra money on a modern hollow point tested specifically for short-barrel pistols, not whatever’s cheapest at the counter.
Where .45 ACP Still Makes Sense
.45 ACP carries a devoted following for good reason. It’s a mature cartridge with a long service record and plenty of loads that meet FBI penetration standards with wide, consistent expansion. The costs are real too: fewer rounds per magazine in most platforms, sharper recoil that slows follow-up shots for a lot of shooters, and guns that tend to run larger and heavier for concealed carry. I recommend it to students who already shoot it well and want to stick with a caliber they’re comfortable with, not to beginners looking for a first carry gun. Comfort and control beat raw bullet diameter every time I’ve watched it play out on the range.
Florida’s Legal Side Doesn’t Care What Caliber You Pick
Florida Statute 790.06 sets the concealed weapon license requirements at the state level: applicants must be at least 21 years old, a U.S. citizen or qualifying resident, free of disqualifying felony or controlled-substance history, and physically able to safely handle a firearm, with licenses valid for seven years once issued (Florida Statute 790.06). None of that touches caliber. Florida doesn’t restrict which cartridge you can carry concealed, and neither state law nor any federal statute sets a minimum penetration or stopping-power requirement. The FBI’s 12-to-18-inch figure is a law enforcement testing benchmark, not a legal mandate for civilians. This is education, not legal advice, and if you have questions about your specific situation you should talk to a Florida-licensed attorney.
What I Tell Students in Palm Beach and Port St. Lucie Classes
Pick the gun first, then the caliber follows. A carry pistol you leave at home because it’s uncomfortable protects nobody. I’ve had students in Wellington and Port St. Lucie show up with brand-new .45s they bought based on a YouTube video, only to switch to a 9mm compact after a single range session made the size and recoil trade-offs obvious in person. Try before you buy if you can, rent a few options at a local range, and put at least 100 rounds through anything before deciding it’s your carry gun.
Ammunition costs money to test personally, so lean on published data rather than guessing. Load your carry gun with a modern hollow point from a major manufacturer, verify it functions reliably in your specific pistol with at least two full magazines without a malfunction, and don’t swap loads right before you need them to work.
Next Step: Train With What You Carry
Caliber debates make good range conversation, but they don’t replace training. If you’re carrying daily, get instruction on drawing from concealment, working a compressed grip under stress, and running the specific gun and load you’ve chosen. Call me at (561) 213-2974 or email Mike@suburbanprotector.com to set up a lesson before your next range trip, and bring whatever you’re currently carrying so we can check it together.