I’ve had an interesting series of exchanges with a correspondent in New Jersey concerning the best handgun for self-defense there.  Since many of my readers live in states with firearms laws that are as restrictive as NJ’s (and in some places, such as New York and Connecticut, show signs of getting even worse), I thought the subject might be of more general interest.The first point is that in New Jersey, it’s virtually impossible to get a carry permit unless you have outstandingly good political connections.

The ‘system’ there is designed to issue as few permits as possible.  Furthermore, there are severe restrictions on the carrying and use of hollow-point or expanding ammunition in one’s handgun.

(That restriction doesn’t apply to law enforcement personnel, of course . . . yet another reason for resentment.  If it’s good enough for cops, why shouldn’t it be good enough for honest citizens whose taxes pay those cops and buy their ammunition?)
These restrictions upset the normal calculation about what cartridge or round New Jersey gun-owners (and others suffering under similar restrictions) should use for self-defense.

Modern bullet technology has brought many common defensive handgun cartridges to a much higher level of performance.

However, if that technology can’t be used, cartridge effectiveness must be assessed in terms of older measurements.  I’m obliged to the anonymous editor of the Firearms History blog  for his very useful articles on the following systems of measurement:

• Kinetic energy
• Momentum
• Taylor KO Factor
• Thorniley Stopping Power Formula
• Hatcher Formula
• Optimum Game Weight Formula

Follow each link for more information about the formula in question.  Not all are useful in a defensive context, but they’re all informative.  (We’ve discussed some of them in articles here.

As an old Africa hand, I’m partial to the Taylor KO measurement as an indication of the effectiveness of solid [i.e. non-expanding] bullets.

It squares with my experience of shooting in Africa, be the target an animal or an enemy.  In particular, I agree with its bias towards larger-diameter bullets when dealing with solids.)
To get back to the self-defense situation, if gun-owners are restricted in their use of expanding handgun ammunition, they have to choose the most effective cartridge available under those restrictions.

That immediately argues against most smaller calibers, because (according to most of the above formulas, and also on the basis of hard-earned experience) they’re less effective than larger ones in a defensive role.

Furthermore, one of the primary advantages of smaller cartridges is that one can fit more of them into a handgun of a given size compared to larger cartridges.

However, if (thanks to restrictions on bullet technology) each cartridge is rendered less effective, more of them will be needed to neutralize an opponent than larger ones;  and if magazine capacity is also legally restricted, that means that a greater percentage of your rounds will be needed per opponent than if you used larger ones.

Example:  if it takes 4-5 9mm. Parabellum ball rounds to stop an assailant, and you only have 10 of them in your gun, you’ll use up to 50% of your ’rounds on board’ to stop each opponent.

If it takes 2-3 .45 ACP ball rounds to do the same thing, and you have 10 of them in your gun, you’ll be able to deal with twice the number of attackers for the same expenditure of ammunition.
Despite modern attempts to reinterpret historical data, it’s clear that throughout the blackpowder era, bigger, heavier bullets did a better job of stopping a fight in a hurry than smaller, lighter ones.

That’s why the most widely used handgun cartridges up until the invention of smokeless powder were over .40″ in caliber;  for example, the US .44-40, .44 American, .44 Russian, .44 Bull Dog, .45 Colt and .45 Schofield, and the British .450 Adams, .442 Webley,  .476 Enfield and .455 Webley.

Although smokeless powder allowed the introduction of newer, smaller cartridges with similar (or improved) effectiveness compared to their blackpowder predecessors, this was not always the case.

Bigger, heavier cartridges still tended to do better than smaller ones at ending an attack, as the infamous Moro rebellion demonstrated.

It was the experience of that conflict that prompted the US Army to replace its newly-issued Colt M1892 revolvers chambered in .38 Long Colt.  As General Leonard Wood reported in 1904:

“Instances have repeatedly been reported during the past year where natives have been shot through and through several times with a .38 caliber revolver, and have come on, usually cutting up the unfortunate individual armed with it. The .45 caliber revolver stops a man in his tracks, usually knocking him down.”

This led initially to the reissue of older Colt Single Action Army revolvers (the famous ‘Peacemaker’ of the so-called ‘Wild West’), and ultimately to the adoption of the renowned M1911 pistol and its .45 ACP cartridge.

It remained the US Army’s standard sidearm until the adoption of the Beretta Model 92 in 1985, and is still issued by specialist units.  As late as the 1980’s, during investigations following the notorious ‘Miami Massacre‘ that sent shock-waves through US law enforcement, it’s reported that “the FBI rated the .45 ACP twice as effective as the 9 mm“.

That certainly correlates with my experience of handgun use in Southern Africa during that period.
Please note that I’m not by any means opposed to the use of smaller cartridges, provided that modern bullet technology is used.

My daily carry pistols are chambered for the 9mm. Parabellum cartridge, for reasons outlined here.  I load them with either Winchester Ranger T-series 127gr. JHP +P+ or the more recent Hornady Critical Duty 135gr. JHP +P rounds, and trust both to do a good job in defense of my life if necessary.

The latter round in particular is attracting serious interest due to its performance under all likely circumstances, as outlined in this video from Hornady.  It’s reported to be the only range of handgun ammo to pass every FBI test criterion with flying colors.

However, if for some reason I couldn’t carry expanding ammunition, my instant response response would be to revert to handguns chambered in .45 ACP or .40 S&W[respectively my first and second choices], loaded with the best-quality ball rounds I could find.

That’s why I keep firearms in my safe chambered for both cartridges.  Furthermore, as Jim Higginbotham points out, it’s hard to make a .45 ACP bullet perform badly!
The late, great Jeff Cooper used to opine that an adequate defensive bullet in a handgun, irrespective of bullet type, shape, etc., should be at least .40″ in diameter, weigh at least 200 grains, and exit the muzzle at a velocity of at least 1,000 feet per second.

Multiplying those factors together, we arrive at a total of 80,000.  If we use those factors and that total to assess the effectiveness of the most common semi-auto pistol cartridges, using ball ammunition, we can see how they stack up against each other:

• .45 ACP:  .451″ x 230 grains x 830 fps (US Army standard ball) = 86,096
• .40 S&W:  .401″ x 180 grains x 1,020 fps (Winchester Q4238) = 73,624
• 9mm Parabellum:  .355″ x 115 grains x 1,190 fps (Winchester Q4172) = 48,582

Those values are pretty much in line with what the older measurements (referred to above) give us in terms of bullet effectiveness, and in line with extensive experience ‘on the street’.

They also bear out the FBI’s finding during the 1980’s that the .45 ACP round was about twice as effective as 9mm. Parabellum.  The more modern ‘intermediate’ .40 S&W round (introduced in 1990) falls between them in performance according to Cooper’s scale.

I’m confident enough in either .40 S&W or .45 ACP ball to use them for defensive purposes if necessary.  As long as I put enough of them in the right place(s), they’ll get the job done.
Of course, one can never rely on a single bullet being sufficient to stop an attacker.  I’ve covered this extensively in three articles dealing with ‘The myth of handgun “Stopping Power”.’

For that reason, the most effective cartridge/bullet combination should be chosen, and enough of them should be delivered to do the job.

If the magazine capacity of one’s pistol is restricted, this means that expending four or five smaller rounds on each attacker can rapidly empty one’s gun, rendering it useless until reloaded.

Far better to have larger, more capable rounds in the gun, each one as effective as possible, so that the same magazine capacity will allow one to deal with more attackers.
What handgun to carry it in?  That’s very much a matter of personal preference.  Some prefer the ‘old reliable’ 1911 pistol, and I certainly can’t argue as to its effectiveness.

Some more modern full-size .45 ACP pistols, such as the Glock 21, the Springfield XD or the Taurus 24/7, have improved on the 1911’s limited ammunition supply, and hold 13-14 rounds.

Unfortunately, as far as my hands are concerned, this makes their grips too ‘fat’ for comfort.  I prefer a narrower grip that I can grasp more firmly.

My choice is the Ruger SR45.  Its magazine holds only 10 rounds, but that allows its grip to be much slimmer, making it easier for me to grasp;  and the gun’s slightly greater weight helps me to absorb the cartridge’s recoil during extended practice sessions (don’t forget, I have health limitations, so that’s an important factor for me).

Some other gun writers don’t like the Ruger SR series, but I do.  Ed Head, instructor, Rangemaster and former Operations Manager at Gunsite Academy, offered high praise in his review:  “If I could go back in time to my Border Patrol days I would take the SR45 with me for a duty pistol. It’s that good.“

Mine have proven reliable in my hands, and it’s easy to disable their magazine safety (a feature I detest on any defensive handgun).  I’ve standardized on this model as my full-size .45 ACP pistol.

In .40 S&W, I’ve standardized on the Glock Model 22 and Model 23 (just as, in 9mm. Parabellum, I’ve standardized on other Glock models).
Small .45 ACP pistols tend to be uncomfortable to shoot for extended periods, because they don’t have the heft or the weight to absorb as much recoil as larger weapons.  There are many possibilities out there, ranging from the Glock 36, to Springfield’s XD-S, to Kahr’s CW45 (the model I use) and many others.

I don’t normally carry a small pistol chambered for such a big cartridge, because I find it painful to practice with them for extended periods.

However, if I were denied the ability to carry expanding ammunition and/or a high-capacity magazine, I’d live with the discomfort and switch to my Kahr CW45 in a heartbeat for deep-concealment scenarios (i.e. pocket or ankle carry – I’d rely on my Ruger SR45 for ‘normal’ holster carry).  I also have a Glock 27, which would be my ‘go-to’ small pistol in the .40 S&W cartridge.
One final point.  Big cartridges such as the .45 ACP are relatively expensive compared to their smaller counterparts, because their manufacture consumes larger quantities of metals, propellants, packaging, etc. (and, being heavier and bulkier, they cost more to ship).

That’s one reason why I keep on hand similar handguns chambered for smaller rounds, so that I can train with them at lower cost.  For example, a Ruger SR45 can be ‘twinned’ with a Ruger SR9 for training;  a Glock 22 with a Glock 17;  a Glock 23 with a Glock 19;  a Springfield XD-S in .45 ACP with its sibling in 9mm. Parabellum;  and so on.

Over time, the savings in ammunition add up;  and because the firearms are identical to one another in every important respect, training on the smaller-caliber weapons is directly transferable to their bigger brothers.

All one needs to do is fire the larger cartridge sufficiently to remain familiar with its recoil and trajectory.
Peter