When it comes to defensive ammunition, a lot of people opt for +P loads as a matter of course. It’s certainly not a bad idea on paper; many police departments and federal agencies carry +P or +P+ in their duty guns.
The additional powder load nets an increase in velocity over standard rounds – though how much can actually vary – with the idea being that a jacketed hollow point round traveling at a faster speed will hit the target harder, penetrate deeper, and the result of the extra “oomph” – due to the increase in hydraulic pressure on the bullet – result in more reliable and wider expansion.
Naturally, the attributes of penetration and expansion are desired when it comes to a defensive pistol round.
However, this comes at a cost. The first cost is in increased recoil. As an overpressure round will exert a bit more recoil on the shooter (though some of us don’t mind too much) which can actually impede accuracy with some shooters.
When a person doesn’t like to shoot a round they tend to flinch or tense up prior to squeezing the trigger, a common reason for pulling shots off point of aim. Use of +P also accelerates wear on the barrel, the frame and the recoil spring in a semi-auto, requiring service or replacement of parts sooner than would otherwise be needed.
Granted, the typical civilian isn’t going to fire enough +P to wear out a pistol and, truth be told, neither are many police officers. That’s why police trade-in guns are usually a pretty safe buy. But is the extra velocity actually worth the extra recoil or the potential expense?
There’s a similar debate among waterfowlers, who are already thinking “not that stupid 3-½” shell thing again.” For those unaware, a 3-½” 12-gauge shotgun shell holds the same load as a 10-gauge shell, so you get a bit more shot and a bit more velocity with a slightly bigger shell. The argument (ongoing for decades) is over whether a 3-½” 12-gauge shell actually nets enough ballistic performance to merit the pain of shooting one.
A 2013 Field and Stream article by Phil Bourjaily attempted to answer that, by doing extensive testing at Federal Ammunition’s ballistics lab. For that test, they compared a 3-½” shell with a 3″ shell, both loaded with steel BB shot. The larger shell put 77 pellets in a 30-inch circle target at 40 yards. The smaller round put 63 in the same area, about 72 percent. Shot strings were 49 and 42 inches, respectively. The larger shell gave pellets faster ride – 1500 feet per second vs 1450 fps – but penetration turned out to be five inches in ballistic gel.
In other words, its’ an improvement…but not much of one.
Is it the same with +P ammunition?
Ballistic gel is a poor simulation for human flesh, and even if you add a few layers of clothing, it doesn’t come all that close. However, it comes closer than shooting a bullet into a water barrel.
The fellas over at Lucky Gunner Labs maintain a ballistic testing database, where they fire various self-defense loads and catalogue the penetration, expansion and velocity. While not perfect, it still gives you an approximation of how well rounds perform.
As for +P…it depends on the load, but when compared to a standard pressure JHP variant, it usually doesn’t buy that much more in terms of performance. For instance, their tests of Federal 124-gr 9mm HST rounds had the same penetration in both pressure loadings. The +P variant gained an average of 33 feet per second (1168 fps vs 1135 fps) and an average of 0.05 inches in diameter when fully expanded.
In the 147-gr load, Federal 9mm HST +P did penetrate an average of 1.5 inches deeper compared to standard pressure (17.7 vs 19.2) gained an extra 46 feet per second (1008 vs 962) but expanded drastically more, with standard pressure averaging .38 inches to the +P’s .60 inches.
Hornady’s Critical Duty 135-gr load in 9mm actually penetrated more deeply in standard pressure (19 inches vs 18.1 inches) though the +P loading gained 65 feet per second in velocity. Expansion was only marginally better in the +P loading.
Speer Gold Dot likewise only netted a gain in velocity in the 124-grain load of 9mm, with 1141 fps vs 1067 fps in the standard pressure load. However, that velocity didn’t net deeper penetration (the opposite; 16.4 inches vs 18.1 inches in standard pressure) and expansion was only 0.02 inches greater in the overpressure round.
And so on. There are other similar examples in their results.
Again, ballistic gel testing isn’t a great facsimile for actual ballistic performance in human bodies, but can at least provide an objective measure of how a bullet will perform. Additionally, plenty of officers have been able to trust their lives to +P ammunition and gotten good results with it.
However, it could be stated that +P ammunition is not, strictly speaking, a necessity, as the gain in speed and penetration isn’t necessarily astounding. Plenty of standard pressure loads will more than do the job.
Oh, and one more thing: you only need 3-½” shells if you’re a bad shot. Until next time!