Since we aren't supposed to talk about politics and religion in polite company; that can be a difficult question to answer, but what the hell, I'll give it a shot...
Ooooh sorry about the bad pun, it was entirely unintentional.
Where to begin...
Well, basically you've got two categories of commonly commercially available defensive chamberings, one for revolvers, and one for auto pistols (with some limited crossover).
Theres a fair but limited selection of choices within those categories; each appropriate to a different situation, or a different weapon.
What are the factors to consider, leaving out the choice of a particular weapon?
1. Wounding capability: Tied for the most important factor in choosing a defensive caliber is it's wounding capability. The more effective the caliber, the better it is right? Well, yes, up to a point; because it has to be balanced with the other factors, or else we'd all be shooting 10mm and .44 magnum.
2. Shootability: The other half of the tie with wounding capability; if you can't shoot it well, it doesn't matter how good the chambering is at wounding. Misses don't count for half points when you are defending your life.
Some folks can eat the recoil of a .44 mganum or full power 10mm all day long; some have trouble with the 9mm. Also, some chamberings are inherently more or less accurate and precise than others.
Oh, and the next factor (packability) makes a big difference in shootability, so you need to take that into consideration as well when making your choices.
3. Packability: The size of the cartridge, and of the gun, effect how likely you are to have the weapon with you when you need it. Generally speaking, the bigger the cartridge, the bigger the gun; or the fewer rounds it can hold.
If your only defensive need is a bedside gun, than get the biggest thing you're comfortable with (both in caliber and in gun size), because it will be more effective, and probably shoot easier (the extra weight). If packability wernet a primary consideration, no-one would shoot anything smaller than .45acp. If on the other hand you are in Arizona in summer or carrying concealed to the beach... well lets just say Kel-Tec is successful for a reason.
4. Ease of acquisition: I'll say this right now, and a lot of folks may disagree with me (but most of them have their own reloading bench and know how to use it); if you can't buy at least one decent loading of the caliber at your local WalMart (assuming you live in a free state), you shouldn't consider that cartridge for a defensive weapon. By the same token if there arent at least a few guns in the chambering in your local gun store, I wouldn't even consider it.
Also, there have to be sufficient defensive loads available for the weapon so that you can find one it likes; and so that you have an option to buy it at all when it comes time. In a lot of less common calibers you will only find practice ammo (white box hardball and cheapo JHP)
For example, I think the .32 H&R magnum could be a great defensive cartridge; because it's relatively powerful but can be chambered in a remarkably small revolver (because it's a very long and skinny case). Unfortunately I wouldn't recommend it to anyone as their primary defensive choice; because you are going to have a hard time finding ANY ammo for it, never mind decent defensive ammo, at a local store.
5. Cost of ammunition: If ammo is cheap, you will practice more. If you practice more you will shoot better. Conversely if ammo is expensive, you will shoot less. WAY less. That is self evidently a bad thing.
So, given these factors, what chamberings do I think people should generally consider?
Defensive Auto-pistol Chamberings
.22 lr: There are a few things that make the .22lr a serious considerationAuto-pistol Reccomendations:
No, I'm not going to recommend this be your only defensive handgun chambering, but it's not something you should discount completely either. If nothing else it is absolutely the best practice weapon, and about the most fun. You learn more basic shooting technique firing 500rds of .22 than you do 50 rds of 9mm for the same price (yes, that's how cheap .22lr is).
- First of all it's tiny; in fact it's the smallest commonly available caliber (well, other than .22 short). That means you can have a very small gun that can tuck in almost anywhere, and still carry a lot of cartridges.
- Second, it's VERY easy and fun to shoot. More fun, means more practice.
- Third, it's very very CHEAP to shoot. Cheaper ammo means more practice
The trick with using a .22 as a defensive chambering is this: Pick a gun with a big magazine, always have it with you, when you have to use it, empty it into the scumbags face from 5 feet away, then run as fast as you can.
.380ACP: Much like the .22, the .380 is small. It's not the smallest commonly available centerfire pistol round (that distinction falls to the .25acp - which is less powerful than the .22 magnum, and only slightly more powerful than the .22lr - don't even consider it), but it's the smallest round that has useful and effective defensive ammunition commonly available for it.
With modern bullet technology, in a high pressure loading, the .380 can be more effective than 9mm hardball, and almost as effective as 9mm hollowpoints (at least at short range anyway. The .380 is a 5-7 yard cartridge as far as I'm concerned).
As with the .22, being small means you can have a small pistol wrapped around it. My backup/pants pocket gun is a KelTec P3AT in .380, and it's smaller than my wallet (and weighs less). It goes into my pants in the morning, comes out when I get ready for bed; and I ALWAYS HAVE IT.
The most effective gun in the world is useless if you don't have it with you.
The downsides? Well .380 is less effective than just about every other centerfire chambering. Also, it can be a handful in most of the small guns chambered for it; especially since most of them are straight blowback designs.
Also, they are making 9mm pistols as small as most .380s these days (though generally not as small as the KelTec), so if you don't need a pants pocket gun, one of the ultra mini 9mm offerings may be a better choice. The Smallest Kahr 9mm is only slightly bigger than my Kel-Tec (about 1/2" taller, the same length, but twice the weight) and the new (and incredibly expensive and impossible to get) Rohrbaugh is almost the same size (1/4" taller, same length, and 50% heavier).
9x19: This is the "default" defensive choice for the majority of the worlds military forces, (including our own, for now), and the most common chambering of any certerfire handgun outside the U.S. (here it's .45acp, and 9mm is second).
The 9mm is a small, relatively high pressure, relatively high velocity loading. It's chambered in just about evrey size and weight of handgun from tiny pocket guns (like the Rohrbaugh), to full size 18 shot bullet hoses like the Glock 17.
9mm is generally considered the easiest "full power" cartridge to shoot, having mild recoil and report even in snappier loadings. In a full size pistol, the hottest 9mm loads are far easier to shoot than a compact .380 (and of course that fullsize pistol holds a lot of them).
With modern bullet technology the 9mm is a decent stopper; and is ideally matched to the more compact designs like the Kahr K9 that I carry regularly. I love the gun, and with the right +p hollowpoints I dont feel underarmed.
If you're going to go with a full sized gun however, you might as well step up to a more effective caliber. There's no reason to choose 18 rounds of 9mm over 16 rounds of .40S&W (or .357 sig) or 13 rounds of .45acp.
Also, it's important to note that the performance of 9mm's is predicated on a modern premium expanding bullet. If those are unavailable to you (if you're a soldier shooting at an organized enemy, or if you live in New Jersey for example) or if the bullets fail to expand (which happens a lot), that performance goes out the window, and the 9mm is not much more effective than the .380.
Oh and one of the biggest advantages of the 9mm is that it is the cheapest and most available centerfire chambering to shoot, because of the mass popularity of 9mm around the world. EVERY shop that sells centerfire pistol ammo, anywhere in the world, will have 9mm (this is not always the case with .45 outside the U.S.).
.357SIG: The .357 sig is an attempt to get .357 magnum ballistics into a medium sized auto-pistol frame; and it has been mostly successful at doing to. The .357sig takes a 9mm bullet (which can be the same size as the .38spl and .357 magnum bullets), and necks down a .40s&w case to hold it. Then they turn the pressure up; and in the top end loads, the chambering approaches the power of the .357 magnum, which is historically the most effective defensive pistol caliber in civilian use.
Sounds great, why isn't every gun made in .357 sig? Well, you are cramming a pretty hot round, into a medium sized gun, and that has some side effects:
Generally speaking the guns that are chambered in .357sig are converted from designs intended to fire the .40S&W, a much lower pressure round. In many cases those .40s&w guns were just scaled up 9mms to begin with. So yes, some guns have a problem with the SIG.
- It's VERY snappy. Some people have a problem with the recoil
- It's VERY loud. Lots of powder, high pressure, high velocity, big muzzle blast etc...
- It's a lot harder on guns than either the 9mm and the .40S&W
Personally I LIKE the recoil of the .357SIG, because it's a fast recoiling round, which allows for a faster recovery for follow on shots; and also allows for better doubletaps.
Also, I don't buy low quality guns, or poorly designed ones. If you stick with new production SIG, Glock, HK, Springfield, Beretta, and Taurus; you shouldn't have any kind of problem there. You MIGHT be a bit wary about used guns in this chambering though.
The biggest disadvantage to the round as I see it, is that the .357sig isn't as widely available as the other chamberings listed here, and is generally a LOT more expensive.
.40 S&W: The .40 S&w was an outgrowth of the 10mm cartridge. When the 10mm was initially developed as a combat round for the FBI, many agents found that it had more recoil than they wanted to handle on a regular basis. Also, the armorers found that it was harder on their chosen guns (the first generation of S&W's 1006) than they wanted. The FBI then requested that a less powerful loading of the 10mm be developed for general duty use.
Well, S&W, Remington, Winchester, and Norma all noticed that they could shorten the case quite a bit, and still give the same performance of the reduced power 10mm load; in a smaller and lighter pistol, at lower cost.
If that seems like a pretty good idea, it is. The .40s&w has taken off like a rocket, and is now the second most popular chambering for police agencies behind the 9mm. Correspondigly, it is also very popular with defensive pistol shooters; because it offers a very good balance between power, control, and overall size.
The .40 can be fit into pistols that are designed for the size of the 9mm, if they are just a bit overbuilt (like Glocks and Kahrs), or with a little internal re-inforcement; but it gives you a significantly more powerful, and more effective cartridge. Better, you generally only lose a single round capacity (sometimes two) moving from the 9mm to .40.
The only major issue that .40 seems to have is that some pistols that were scaled up from 9mm weren't properly strengthened for the higher pressures (the same problem 10mm and .357SIG have, but to a lesser degree).
A minor issue is that .40s&w isn't as inherently accurate as 9mm, 10mm, or .45acp; but at defensive ranges this doesnt make much difference.
Also, the anti-Glockers will get bitchy if I don't mention this, but some have found that Glocks .40 chambers are a bit too loose, and contribute to case head separation or case splitting in +p rounds, or in reloaded rounds. This can cause your pistol to go Kaboom! which is of course a very bad thing; but I don't think the problem is unique to Glock, and it is almost always overstated by the anti-Glock folks.
10mm: The 10mm was originally developed as a high end combat and competition pistol round, to rival the medium magnum revolver chamberings in an auto pistol.
Full power 10mm is roughly comparable in energy to the .41 magnum (which is roughly the same size); and has proven to be a very effective wounding round. In fact it is powerful enough to take medium to large deer.
Of course that power comes at a price. The FBI's complaints about the 10mm were overblown, but there IS an issue with a lot of users, and a lot of guns. The 10mm is a handful, especially if you prefer "slow push" type recoil. The 10mm's recoil signature is very snappy, and very fast.
Which of course means I love it. I can recover very rapidly with the 10mm, and drill two very tightly spaced and very destructive holes in my target very quickly.
The other contention... well there's no way around that. The 10mm is HARD on guns. Other than the Glock 20, which is one of the toughest handguns ever built, just about every 10mm autopistol will eventually crack, and long before the same pistol would in other chamberings.
The slide velocities and momentum generated tend to just batter the heck out of the guns, generally necessitating some kind of recoil buffering mechanism to ensure the pistol doesn't crack into peices prematurely.
In particular, 1911 based 10mm designs seem to have the worst difficulties. I don't know if that's just because they are the most common 10mm platforms; or if it is something in the design interacting with the cartridge (I suspect it's some of both); but EVERY 10mm 1911 I've ever seen, shot etc... will fail a hell of a lot sooner than the same weapon in .45acp or even .45 super.
There is one more issue; the 10mm is EXPENSIVE. In fact it's generally about TWICE the cost of the next major caliber, the .45acp. Again that means less shooting, and less shooting is bad.
.45acp (and super): The .45acp is the most popular centerfire handgun cartridge in the United states, and the second most popular world wide. There are more guns chambered in .45 here in the U.S. than any other centerfire caliber, and I suspect more than all of the other chamberings combined (with the exception of 9mm).
There's three reasons for that.
2. The 1911 auto pistol
3. Because it really is just that good
To my mind, the only better defensive auto pistol chambering than the .45 (even including .45 super) is the 10mm; and the 10 has a lot of issues that the .45 does not.
The .45 is a relatively mild recoiling cartrdige; with a high overall recoil energy in comparison to smaller calibers, but a far less sharp, and more diffused "slow push" impulse; that makes the .45 easier to shoot for many, than other chamberings of comparable energy and wounding potential.
It's a relatively heavy (almost twice the weight of a 9mm), relatively slow (30% or more slower than the 9mm), and very big around bullet (about 40% larger diameter than the 9mm). Basically it makes big holes, and doesn't beat up your hand, or the gun, to do so.
Because the .45 is relatively mild, it can also be chambered and handled in guns smaller than the 10mm can be; and in fact not much larger than the .40S&W. For example, I personally carry a Glock 36 frequently. The G36 is the smallest .45 pistol that I'd want to shoot with any regularity, and it can be a handful with +p loads. It's a bit chunky, but VERY compact, and with a finger grip extension (I have very big hands) it's not too bad to handle. Shooting it with standard pressure loads is comparable to shooting my KelTec with the high pressure Winchesters. This is appropriate because both guns share the same philosophy: put the most destructive power in the smallest possible package.
The .45acp is available in a wide variety of loadings, from the marginally powerful reduced recoil rounds (650-850fps at 185-230 grains), to standard hardball (230gr at 850fps), all the way up to +p+ defensive screamers (up to 1150fps at 200gr). Additionally, many .45acp guns can also chamber the .45 super, which is dimensionally identical to the acp, but uses a different case, and is loaded to a MUCH higher pressure, velocity, and energy (200gr at up to 1350fps for example).
Unlike the 9mm, which depends on expanding hollowpoint ammunition for it's effectivenes, .45 is reasonably effective in hardball loadings. Not that those would be my choice, but if you are loading hollowpoints and they fail; the unexpanded .45 is going to be almost as big as a fully expanded 9mm; and generate wounds accordingly. When the hollowpoints perform as designed, that hole is obviosly a hell of a lot bigger.
The .45 is also a relatively inexpensive round. Though certainly much more expensive than .9mm, it is generally less expensive than the other centerfire choices listed here. Less expensive, more shooting, good thing etc...
Finally, this isn't related directly to the cartridge itself; but the pistol design most strongly associated with .45acp is the 1911, a pistol that most expert handgunners regard as the best autopistol design of all time (though certainly not without it's flaws). Even the ones that do not, respect it for the excellent weapon that it is.
The only bad thing about the .45, other than some folks not liking the recoil (this is usually a psychological "it's big and scary" issue, but some folks jsut dont like the "big slow push" of the .45 and prefer lighter and snappier), is that it IS a big, and heavy round. That means pistols designed for it, no matter how tightly shrunk, will always be larger than most of the other cartridges mentioned here.
I'll say it right now, I almost always recommend the .45 acp as the proper primary defensive autopistol cartridge, whether you are beginner or expert. It is the perfect balance of power and control; it's cheap, it's available everywhere, and there are any number of excellent gun choices for it.
As a beginner, the only time I'd recommend something else, is if you can't handle the recoil of the .45 (go to a 9mm), or if you can't conceal a pistol that you are comfortable shooting in .45.
That last one is why I have my Kahr (9mm), and my Kel-Tec( .380), because even a big guy like me needs a smaller gun for lighter clothes. My G36 is pretty small, but it's still too bulky to wear without a covering garment. I can carry the Kahr K9 (and if I had the K40 it's the same size) with a bloused shirt and have it be near invisible; and the KelTec in my back pocket.
And of course, there's always the 1911. I have a couple, I love them. My personal preference is the commander size, which I have no problem concealing with a covering garment, and which balances for me better than almost any other handgun. Lots of people love them, have no problem carrying them etc... but lots of other people DO have a problem carrying them.
For beginners who don't want a .45 for whatever reason (and there are certainly valid reasons no matter what .45 bigots say), I usually recommend they go down to the .40. There are plenty of excellent pistols available in this chambering, in every size from ultra compact to full size. Bascially every design made in 9mm, except the very smallest and lightes, and some of the cheapest; is made in .40.
Now, if you are an expert shooter, then I can't recommend the 10mm, and the .357SIG highly enough. I'm not saying I recommend them over the .45; but I'll put the 10mm right there, and the .357sig only slightly below (it would be my choice for anything smaller than .45).
In particular, the .357 sig in the SIG 229 (or a similar sized pistol from Glock or HK whcih may be jsut as good) is one of the finest and most effective ways of defending yourself I have ever owned; and I recommend it unreservedly.
I don't have a particular 10mm recommendation, because unfortunately so many 10mm pistols have had so many problems. A good custom 1911 or a glock 20 are about the best ways to go, and both are excellent pistols; but it's just something you have to try for yourself. I know one guy who swears by his Glock 29, but I'm not sure I'd want to shoot full bore 10mm through somethign so small, and if you arent going to the full bore, why not just shoot .45 (thus my G36, which is 1/4" taller, but 1/4" thinner and 6oz lighter - though it only holds six to the 10mms ten)
Oh and the 10mm and .357 sig both have one slight advantage over the 45acp (though the super can have the same advantage). They both penetrate soft and medium cover (including soft body armor at close range shooting hardball) very well. The slower moving, wider .45 is more likely to slow down or flatten out. Of course that also means the 10 and SIG are more likely to overpenetrate; but there aint no such thing as a free lunch.
Defensive Revolver Chamberings
.22lr: All of the same arguments apply here as with autopistols; except that you usually have a somewhat reduced capacity, in exchange for even smaller size with a .22 revolver. For example, North American Arms line of mini-revolvers is so small, you can wear them as jewlery, conceal them in a cell phone case etc...Revolver Reccomendations:
.22 magnum: The .22 magnum is actually only slightly less effective as a defensive cartridge than the .380 acp; and is far more effective than the .25acp.
Generally regarded as a small game or small varmint round for rifles; in a mini revolver it can be a useful defensive round. Even better, they are only jsut a little bit bigger than a .22lr revolver. In fact, many of the small revolvers (again like the NAAs) have interchangeable cylinders for .22 magnum and .22lr.
Unfortunately it's not generally available in small autopistols, because it's a much higher pressure round that doesn't cycle well in the straight blowback actions used by most .22lr auto pistols. This means that a pistol manufacture would need to make a new, stronger, and more expensive to produce design, jsut for a pistol that will almost certainly be less popular than the .22lr option... well lets just say it's obvious why most manufacturers don't bother.
That's ok, it jsut leaves more .22mag for revolver shooters.
Oh and as a bonus, .22 magnum (also called .22wmr) is still cheaper than most centerfire ammunition as well; though not as cheap as .22lr.
.38spl: .38 special is the oldest defensive centerfire cartridge (the .22lr is even older) we're considering; being an outgrowth of a blackpowder pistol cartidge from 1884. The .45lc is older, dating to 1873, but it wasn't loaded in it's modern form until the 'teens; and the modern .38spl cartidge dates from 1902. The .38spl really came into it's own however after WW1; when it became the dominant chambering for police issue revolvers.
The .38spl is a long, medium bore, low pressure round; and delivers a light-medium weight bullet at low velocity. As such, it's extremely pleasant and comfortable to shoot; even in some of the smallest revolvers.
It's also available in a VERY wide variety of loadings, from cowboy loads that recoil barely more than a .22 in a full sized revolver, and are less powerful than a .380acp; all the way up to +p+ defensive loads that are more effective than most 9mm loadings.
.38spl has the additional advantage that a gun chambered in .357 magnum, can fire the .38spl; because the magnum is just a stretched and uploaded .38 (the reverse is not true).
Given this, my general recommendation to beginning defensive handgunners is that they purchase a .357 magnum chambered pistol, and shoot mostly .38spl through it.
One more thing, .38spl is CHEAP. It's the only other centerfire caliber that can be as cheap (and in some cases even chaper, though that's rare) as 9mm.
.357 magnum: As mentioned above, the .357 magnum is an outgrowth (literally, it's about 1/5" longer) of the .38spl.
.357 is historically the most effective defensive cartridge in civilian use. It seems to be the sweet spot between usable power, and overpenetration. By this I mean that it's the most powerful chambering that will generally fully expend it's energy in the intended target without overpenetration (though the 10mm is a bit more powerful, and only very slightly more likely to overpenetrate).
Also as mentioned above, guns chambered in .357 magnum can also shoot .38spl, which cannot be overstated as an advantage. .357 magnum ammo is fairly expensive, but .38spl is dirt cheap.
The .357 is chambered in a wide variety of guns, from the ultra small (10 oz) 5 shot S&W scandiums, compact 5-shots like the SP101, medium frame 6-shots from every manufacturer, all the way up to the 8 shot large frames from S&W, Taurus, and others. You will always be spoiled for choice with the .357
The same applies for loadings. The .357 magnum is probably supplied with more effective defensive loadings than any other caliber, and in this I include 9mm and .45acp; because there are a lot of hunting loads that also make excellent defensive loads.
Basically there are only two disadvantages to the .357. One, it is a serious magnum pistol round, which means it's a fairly hard recoiling round. In the smaller pistols it can be quite unpleasant to shoot. This however is offset by the ability to fire .38spl through it. Two, .357 ammo is NOT CHEAP; but again, that is offset by .38spl.
Honestly, the .357 is just about the best defensive chambering there is; and I'd say it absolutely is the best in revolvers (the 10mm is slightly more effective, but also has alot more disadvantages). There are certainly more damaging calibers, but none have the balance of benefits with the lack of drawbacks of the .357, revolver or auto pistol
10mm: There are a number of revolvers available chambered for the 10mm; and they have all the benefits and drawbacks of the 10mm in auto pistols but for one. The 10mm revolvers are stronger than hell, and there is no need to worry about the gun dying a premature death.
Oh, and some find that 10mm's recoil is more manageable in the revolvers chambered for it. That also means you can use more powerful loadings of it should you so desire, without as much difficulty in handling.
.44 magnum (and spl) : Great round. Love it. Very Powerful. Great guns chambered for it...
Don't bother unless you are an expert, or a handgun hunter. Gun shops used to be full of used .44 mganums that were shot once and then sold because the owner didn't know what they were getting into.
We call it the "Dirty Harry" effect.
Oh and the reason I say "used to be full of"? Because after a while, the gun makers made a hell of a lot less of them; because folks just weren't buying all that many new ones. As cool and as great as they are, they are a very specialized weapon, with a fairly limited audience; and that audience has been very well supplied with used models fired once and then sold.
The .44 magnum is a chambering that should only be selected for defensive purposes by handloaders, who can download the cartridge to more appropriate power levels; or wilderness hikers who need the protection from dangerous animals.
Because of it's size and power it is generally only chambered in large, heavy guns; and the few exceptions are so violent to shoot that they are 100% experts only weapons.
The one mitigation to this is that guns chambered for the .44 magnum can load the .44 special (again, as with .38spl the reverse is not true); which is chambered in a number of nice medium framed five shot revolvers. It is an EXCELLENT defensive round, and is not much more difficult to handle than a +p .45acp.
That said, both .44 magnum, and .44spl are ridiculously expensive; the only way they are affordable to shoot is if you hand load.
.45 acp: As with the 10mm, there are several revolvers chambered to accept .45acp. This has all the attendant advantages of the .45 as described above; and really no disadvantage; at least in the available large frame revolvers.
The recoil of +p+ .45acp through a 4" S&W 625 (which I keep as my bedside gun) is as mild as standard pressure .45 through my commander (though the muzzle blast is impressive). Even .45 super loads (which the 625 is more than strong enough for) are relatively mild.
.45lc (and .454 casull): .45 colt, also called .45lc is a very effective cartridge. It is the cartirdge that most people associate with the old west, but since the 1870s it has been modernized significantly (around the WW1 timeframe it was completely converted to modern smokeless powder loadings) ; and is now one of the most effective handgun rounds available.
It's available in loads from just above .38spl power levels (cowboy .45lc loads); all the way up to massive hunting rounds, really designed to be fired from rifles. In that range are some remarkably effective defensive loadings, with a huge variety of different bullet types and designs (the .45lc is a relaoders dream in terms of options).
With Taurus chambering some gorgeous light weight mid-sized titanum revolvers in .45lc, this cartridge is a very serious consideration for winter carry, open carry, wilderness carry etc... S&W is also producing on a limited basis it's 625 revolver in .45lc; and I can't tell you how much I want one.
The .45lc is also a reasonbly priced round; with bulk ammo available for quite a bit less than the price of .44 magnum; though of course much more expensive than .38spl. Defensive ammo can be expensive of course, but you arent going to be shooting all that much of it in comparison to the bulk practice loads.
The .454 casull is lengthened and strengthened .45lc; and it's my personal favorite big bore handgun cartridge; because it give you the option of one of the most powerful handgun rounds there is, but also lets you download to .45lc for practice and potentially carry.
The only problem is, most .454 guns are pretty heavy; and they need to be to handle the power of the cartridge. That said, if you live in bear country I can't imagine a better defensive revolver than the Ruger Alaskan. It may be a handful and a half, but when you need it, you REALLY need it.
Taurus is also producing some smaller .454 guns; and I expect other manufacturers will follow suit.
Well I really think that everyone who owns a handgun should have a medium frame .357 revolver (and a .22 practice pistol). Seriously, it should be a law that every homeowner is issued one of each along with their mortgage.
There is no better balance between capability, shootability, cost etc... than in the .357. The only downside being the medium and large frame revolvers that are more comfortable to shoot it in, aren't very packable. Of course for that we have the ultrasmall titanium pieces; but there is no doubt those are expert only guns.
As to the others, well they are all excellent choices; but I can't say as I'd recommend them as a first defensive handgun.
That said, honestly, I dont think any of the centerfires are a bad choice, except for the .44 magnum, which some folks love; but which is better suited to experts, and to handgun hunting.
The one caveat to that, is that even if you intend on shooting only .38spl, that you buy a gun chambered for .357 magnum. It will be stronger, and give you that extra option in case you ever need it.
Oh and I suppose I should mention the .41 magnum here - because if I don't the rabid partisans of the round will string me up; though I didn't in the listings above. It's an excellent defensive chambering; with loadings from the low 10mm range (.41 special), all the way up to the low .44 magnum range. The problem is, it's almost completely unavailable for anyone other than handloaders (who tend to love it with a passion, go figure); and it's only chambered in the same size guns as the .44 mag; with no particular advantage over it.
The 10mm... well as I said, I love the cartridge, but I don't see any particular advatage to it in a revolver over a .41 magnum or even a .44 special; except that it can be ammo compatible with your 10mm auto-pistol (and if you're lucky your 10mm carbine).
In the same vein, .45acp revolvers are a great thing. I love mine, I highly recommend them; the only issue is, you can get the more effective .45lc in a gun the same size (though again, if you have other guns in .45acp, the ammo commonality is great). The .45lc is only chambered in larger guns, but if you're going to keep it at home, or take it out in the woods with you; I think it's a near ideal choice.
Next holy war, which to choose revolver or autopistol....
UPDATE: The River Dog writes an excellent piece on first handgun selection to tie into this one. Oh and yes, as the man says, this article is a bit long (about 6000 words - it took me about 8 hours two write it), and can be a bit much to absorb all at once.