"I shot a friend's Browning Hi Power 9mm and liked it. Would it make a good self-defense gun? I've heard that 9mm is too weak for self-protection. I like the gun, but not the caliber."
(Hello. The quotes above are fairly typical of questions I get via email on a regular basis and I thought that perhaps a "public" article might better explain my position and save having to respond to this question quite so often. We'll see.)
There are factors besides caliber in determining what makes a "good" self-defense handgun. Reliability is the first thing, regardless of caliber, and the Browning Hi Power has proven itself an extremely reliable pistol. If you are not comfortable with "Condition One" or "Cocked-and-Locked," the Hi Power would not be a good choice for your self-defense pistol. I am very aware that some folks prefer to carry with the hammer down on a chambered round or with the chamber empty and a full magazine, but I cannot recommend anything except Condition One for any single-action automatic. It's more dangerous to lower the hammer on a pistol having a round in the barrel than the perceived danger in having one with the hammer at full cock. Trying to cock the pistol under the stress of attack while possibly in a physical struggle will probably result in the pistol being dropped are too slow into action. Carrying in Condition Three (barrel empty/magazine full) assumes that you'll have both hands free and uninjured when the attack comes. This cannot be counted upon in my opinion. While the Hi Power is certainly "safe" in any of these carry modes, only Condition One allows for instant readiness with but one hand if necessary.
Regarding 9mm vs. 45, it's been my observation that there is probably not much difference between either if you get good hits, and spare me the "hit 'em in the little finger and the forty-five will knock them down." That is simply not true and never has been. It is physically impossible, and I won't argue it here. Those who believe it can do so or do their own independent research to prove to themselves that this old wives' tale is just that! This is not to say that the .45 ACP is not a really good defensive round, only that no commonly used defensive handgun round has the "knock down" effect attributed to the .45 ACP. Still, if looking at the better loads in each caliber, the bigger one probably does have the edge, at least in my view.
If caliber effectiveness is the main criteria for you in your search for a "good" defense gun, you might want to look at calibers other than 9mm. As has been mentioned, .45 ACP can be more effective as can .357 SIG, .40 S&W, and probably .357 magnum in some loads. The question is, "How much more effective?" I don't believe that there is much difference in terminal effect with any of these calibers, assuming that you can hit a coffee saucer size area about midway up the sternum. If you are comfortable with Condition One carry, like the Hi Power and can get off accurate shots with it, then I believe you have a "good" defensive handgun… for you! It might not be for the next guy.
The 9mm/.45 debate is one that will continue as it has for decades. Given equal reliability and a competent user, either will serve well. During my years as a police officer, I'm personally aware of cases in which both 9mm and .45 worked very well and others in which neither had particularly stunning success. I do think that the 9mm is more ammunition-dependent for "effectiveness" than the forty-five, but also believe that there are plenty of good to great factory loads available for it. Personally, I'd feel quite secure with a Hi Power loaded with Federal 115-grain JHP, Remington 115-grain JHP +P, or Winchester "Ranger T" 127-grain +P+. The latter is probably the best overall expanding 9mm load available for self-protection. The other two frequently fail to expand after passing through 4 layers of denim before striking 10% ballistic gelatin blocks. So what? This is designated as "worst case scenario" testing by the folks doing such things and it is a good thing when a round does well in bare gelatin and the same after passing through the denim, but assuming that it does not expand, does that mean that it's totally ineffective? I think not. While I do not agree that 9mm and .45 ball are equivalent, I do believe that there's not as much difference as might have once been believed. I'll bet they're within 8 or 10% of each other, not the 50% spread as opined in the past. I do think the forty-five comes out on top with FMJ. I'll bet a hard ball round through the heart or aorta with either caliber will have a pretty telling effect on your opponent.
What it boils down to in my view is to pick a "decent" caliber and gun and learn to shoot it. You and the handgun actually make the weapon and if you cannot handle the handgun effectively, its caliber is moot. For many of us, the Hi Power is the weapon we handle best at speed. We've practiced with it and find that we can score quick, accurate hits from a pistol we're comfortable carrying cocked and locked and are willing to devote the time and practice to make sure that our competence matches the gun's capability.
It is true that there have been well-publicized failures with the 9mm. Now that .45 ACP is being more used in the police community, I'll bet we see more reported with that caliber as well. Neither of these handguns has enough "power" to put a determined adversary down for physical reasons. The admittedly few men I've seen shot did not instantly drop like a lead weight; there can be a few seconds delay and during that time an excited shooter can put quite a few more rounds into the target. Were they necessary? In some cases, yes, but in others, the suspect probably would have gone on down without them, but the end result is usually, "Man, I told you 9mm was no good. It took five hits to put that bad guy down."
Let the situation be reversed where a good shooter put 5 rounds of forty-five into a felon and the result is likely, "Whew. It took five rounds of forty-five to knock that guy down. Just think if I'd been using a 9mm?" With good ammunition and equivalent hits, I'll bet the difference between the two scenarios is nil.
If you think the Hi Power's the way to go strictly because of magazine capacity, I'd counsel you to rethink this position. Unless you're expecting a wave of enemies at one time, it's been my observation that the first few shots are the ones with which you'll solve your problem … or be beyond caring. The 1911 and other .45 ACP pistols having 7, 8, or 9 shots carry ample ammo in my opinion before reloading is needed. That the Hi Power 9mm (with Pre-ban original capacity magazines) holds 14 is not a bad thing, but it's not as much of an advantage for the civilian defense scenario as might initially be believed.
For myself, the Hi Power points well, feels good, and has proven itself to "work well in the dark." It's a simple design that is prone to few problems over the long-term with but a minimal amount of care, and I'm secure with 9mm. Others choose to go with the Hi Power for protection, but prefer .40 S&W for caliber. No problem here and I think the 10 + 1 ammo capability is plenty. It probably is more effective in its better loads, but the difference just won't be "day and night."
I recall a police firearms qualification some years ago in which a fellow officer had a less than spectacular (and less than passing) score with his 1911. He remarked, "That's OK. I only have to hit 'em in the shoulder and they'll drop." He then went on to disparage my 9mm although he somehow forgot to remark about the score. I find both the .45 ACP and the 9mm to be "easy" to shoot in terms of recoil; I like and trust both, but still believe that the most important factor is the willingness of the user to actually shoot another person and have the ability to get telling shots off quickly under stress. Caliber is secondary when speaking of 9mm, .357 SIG, .40, or .45 in my opinion. Skill and tactics are more important.
So, will the Browning Hi Power 9mm make a "good" defense gun for you? It primarily depends on you. If you can get the hits with the Hi Power and yours reliably feeds your expanding load of choice and you have confidence in the gun/caliber combination, it is probably a "good" choice. If the answer is "no" to any of these, there are probably better choices from which to choose.