If you own a .40, keep a case of range ammo and a tested defensive load, and buy when good bulk listings appear. If you're choosing a new pistol purely on ammo cost, 9mm is usually the cheaper cartridge to feed.
The .40 S&W arrived in 1990 as a shorter, milder version of the 10mm that fit in 9mm-sized pistols. It became a law-enforcement standard for more than two decades. Then modern 9mm hollow points improved, and many agencies, including the FBI, moved back to 9mm for lower recoil and higher capacity. Our FBI caliber history covers that shift.
What the switch means for .40 owners
When agencies switched, a wave of used .40 duty pistols reached the civilian market as trade-ins, often in good mechanical condition. That's good news for buyers. It also means there are millions of .40 pistols in civilian hands, so manufacturers keep producing the ammo. .40 isn't going away; it has simply moved from the top of the market to a solid second tier.
Cost per round vs. 9mm
.40 generally costs more per round than 9mm because it uses more material and sells in lower volume. The gap varies with the market, so compare current listings rather than assuming. If you shoot a lot, the difference adds up over thousands of rounds, which is why some owners add a 9mm conversion barrel where their pistol maker supports it.
How much to stock
Treat .40 like any regularly used caliber. For a pistol you shoot a couple of times a month, a case of range ammo is a practical unit and usually clears shipping thresholds. For a pistol that mostly sits in a nightstand, a few hundred rounds of practice ammo and a tested defensive load are plenty. Our 1,000-round baseline shows how to size your number.
.40 S&W ammo (all loads)
The full .40 page. Check which case quantities and hollow points are in stock right now.
Bulk handgun ammo
The broader bulk handgun category, where .40 cases show up alongside other calibers.
Choosing range ammo
The common range weights for .40 are 165 and 180 grains. Heavier bullets tend to feel more like a push; lighter ones can feel snappier. If you carry a specific defensive load, practice with FMJ of a similar weight so your range work carries over. Brass-cased ammo from major makers is the safe default for a pistol you depend on.
Defensive ammo
For carry or home defense, choose a modern hollow point from a major maker and test it in your pistol. Fire at least a few magazines to confirm reliable feeding, and check that it hits close to your sights at typical distances. After that, keep a modest supply and rotate it periodically. Our FMJ vs hollow point guide explains the difference.
Should you switch to 9mm?
Spotting a good .40 bulk deal
Because .40 sells in lower volume than 9mm, bulk listings come and go. The best approach is to know your target. Decide on the brass-cased FMJ weight you practice with, note what a fair per-round figure looks like over a few weeks, and buy a case when a listing meets it. Count shipping in the math, since heavier cases can tip the total. Our shipping threshold guide explains how weight and free-shipping minimums interact.
Avoid chasing the absolute lowest listing if it's an unfamiliar brand or remanufactured ammo you haven't tested. A case that jams in your pistol isn't a bargain.
If you like your .40 and shoot it well, there's no urgent reason to switch. Ammo remains widely available. If you're buying a new pistol and cost per round is a priority, 9mm is usually the more economical choice, and modern 9mm defensive loads perform well. Either way, the best caliber is the one you practice with enough to shoot confidently.
Key takeaways
- .40 S&W remains widely produced because millions of pistols are still in use.
- It usually costs more per round than 9mm; compare live listings.
- Buy a case for regularly used pistols; a few hundred rounds for occasional ones.
- Practice with FMJ close in weight to your carry load.
Product links go to Ammunition Depot through affiliate links; we may earn a commission. Stock and pricing change often, so check the live listing.
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FAQ
Is .40 S&W being discontinued?
No. It remains widely produced for the large number of pistols in civilian use.
Why did police switch from .40 to 9mm?
Improved 9mm hollow points, plus lower recoil and higher capacity, led many agencies back to 9mm.
Can I shoot 10mm in a .40 pistol?
No. Never fire a cartridge your barrel isn't marked for.
Are police trade-in .40 pistols a good deal?
Often, but inspect condition and check the specific pistol's history and parts.