One of the reasons that 9mm guns are more effective today than ever before is the performance of modern 9mm ammunition. Of course, improvements are not limited to 9mm – .45 ACP performance, at it’s lower velocity, is also in a golden age.
Before we talk about some great ammunition options for the Springfield Armory XD-S, we need to spend a minute discussing bullet design.
Modern self-defense expanding ammunition considers opposing factors to gain the best overall performance – penetration and expansion. Both of these attributes are impacted by velocity. More velocity tends to drive expansion at a faster rate. At any given velocity, a bullet can expand less rapidly and penetrate more, or expand more rapidly and penetrate less. It’s kind of like diving into a pool. If you enter the water vertically, with your hands pointed in front of you like an olympic diver, you’ll go deeper. If you jump off the board and do a spectacular belly flop, you won’t go very deep, although you may wish you would quietly sink to the bottom, thereby ending your misery.
When ammunition companies design a specific round, say a 9mm, they will create a bullet that will travel a certain depth into standardized ballistic gelatin at an expected average velocity for the caliber in an “average” gun. So, as an example, ACME Road Runner Blaster 9mm ammo might be expected to fire at 1,150 feet per second from something like a Glock 17. ACME might design the bullet to penetrate somewhere in the 10 to 14 inch range while expanding fully.
Why all this diversion into ammunition design? Here’s why. While there are numerous ifs and caveats, the shorter a handgun barrel is, the lower the velocity of any given bullet. A rule of thumb is that a handgun will generate 50 feet per second less velocity for each inch lost in barrel length. The Springfield Armory XD-S has a 3.3 inch barrel, so when compared to a full size gun with a 5 inch barrel, you might see velocity for any given ammunition reduced by as much as 80 to 100 feet per second. So, when fired from a shorter barrel, a bullet designed to expand properly at 1,100 feet per second may not expand at all when traveling at 1,000 feet per second. Conversely, a bullet designed to expand properly at 1,000 feet per second may over-expand, and not penetrate enough, when fired at 1,100 feet per second. Is this bad? No, just different.
With the huge popularity of compact pistols similar to the XD-S, some ammunition companies, like Speer have designed ammunition optimized for proper performance in shorter barrels. For example, rather than designing a bullet to expand at a desired rate when traveling 1,100 feet per second, they design bullets to expand at the desired rate when traveling at 1,000 feet per second.
What does all this mean? It’s not enough to just buy any old self-defense ammunition off the shelf. You need to carefully choose your ammunition, considering the gun you’re buying it for. In my testing, I’ve found that Speer’s Short Barrel ammunition line is an outstanding option for guns like the Springfield Armory XD-S. Let’s take a look.
Speer Gold Dot 9mm 124 grain Short Barrel Hollow Point
I wanted to test multiple Speer Short Barrel loads, in multiple calibers, from the same gun. The Springfield Armory XD-S presented the perfect opportunity. Except for caliber, capacity and a very slight weight difference, the .45 ACP and 9mm XD-S are identical.
Almost any bullet will expand almost every time if you just shoot it into water, gelatin or even soaking wet newspaper. As I care about at least trying to replicate some degree of real-world performance, I always shoot through some type of barrier like layers of clothing.
For the Speer Gold Dot 9mm Short Barrel test, I got somewhat cranky and put two layers of leather and four layers of fabric in front of my super-duper sophisticated soaking newsprint bullet catcher. That’s a pretty tough barrier, but when you consider things like jackets and coats in cold weather environments, it’s more realistic than nothing.
As you can see from the photo, the projectiles expanded perfectly – even with the leather and fabric barrier. Being a bonded design, where the jacket of the projectile is chemically bonded to the interior lead core, none of the bullets came apart. Just what you want.
Speer Gold Dot .45 ACP 230 grain Short Barrel Hollow Point
I’ve found that full weight .45 ACP ammunition is tricky when it comes to expansion. Given the “standard” velocity of a 230 grain .45 ACP projectile at somewhere in the neighborhood of 850 to 900 feet per second, expansion is tough. Every few feet per second of velocity matters when you want the metals in a projectile to spread apart as it travels through tissue. Of course, lots of folks don’t really care as the .45 ACP is a large and heavy bullet even when it doesn’t expand.
But hey, we’ve got modern ammunition technology at our disposal, so I tend to favor ammunition that expands anyway – big .45 bullet or not.
The Speer Gold Dot .45 ACP 230 grain Short Barrel hollow point has advertised velocity of 820 feet per second out of a three-inch barrel gun. The difference is that the projectile itself is designed to expand with less velocity. I fired the bullets shown here through four layers of denim into a big bucket of thoroughly soaked newsprint. As you can see, expansion was right on target. Pun intended. Like all other Gold Dot projectiles, these bullets are bonded so they stay together except under the most extreme circumstances.
Other Ammunition Options
I test a lot of ammunition and continue to be a big fan of most Speer Gold Dot loads, because they work. I’m especially impressed with the Short Barrel offerings based on how they perform in the Springfield Armory XD-S.
With that said, there are plenty of other options out there. Generally speaking, in a gun with a short barrel like the XD-S, I would personally choose a lighter weight .45 ACP bullet in the 160 to 185 grain range. Why? Velocity. All else equal, a lighter weight bullet is easier to push faster. As we discussed earlier in this chapter, velocity aids expansion. So, in theory, a 160 to 185 grain bullet, moving faster, is more likely to expand when shot from a short barrel gun like the XD-S.
We’re entering opinion territory here and I’m just sharing my personal preference based on the testing I’ve done. Non-expanding, full metal jacket .45 ACP ammunition has performed well for over a century, so you may not care whether your particular choice of bullet is an easy expander or not. That’s OK. My goal here is to help you make a more informed decision, as all ammunition is not the same.