Best Ammo for the Glock 17

The Glock 17 is chambered in 9mm Luger, also written 9x19 and sometimes 9mm Parabellum. Those are three names for one cartridge, and any ammunition sold under any of them fits.

That is the entire compatibility question, and it is worth stating plainly because the near-misses are where people get hurt. 9x18 Makarov is not 9mm Luger. It uses a wider 0.365 inch bullet against the 0.355 inch bore of a 9mm Luger barrel, and it is a different cartridge that happens to start with the same number. .380 ACP, also called 9mm Kurz or 9x17, is not 9mm Luger either. Neither belongs anywhere near a Glock 17 magazine.

What is left is the actually interesting question: of the hundreds of 9mm loads that will all function in this pistol, which ones should you buy. That depends on two specifications of the gun itself.

The Gen 5 Glock 17 has a 4.49 inch barrel and a 17 round magazine. The barrel length is the number that matters for ammunition selection, because defensive hollow points are engineered around an impact velocity window and barrel length is what sets the velocity. 4.49 inches puts the G17 squarely in service-pistol territory, which is convenient: it is the length nearly every defensive load in the United States is developed and tested against. You are buying for the baseline case, not for an edge case.

A Glock 17 is close to the easiest pistol in existence to feed. It is a full-size, service-length, loosely-toleranced striker-fired gun with a generous feed ramp, and it will digest essentially any factory 9mm you put in it. That means practice ammunition selection collapses to a single question: what is cheapest delivered today.

Brass-cased full metal jacket in 115 or 124 grain from any established loader is the correct default. In the feeds we track, Winchester, Magtech, Blazer Brass, PMC, Fiocchi and Remington all show up in volume, and which of them is actually cheapest to your door changes week to week. That is why there is a live price block above this section rather than a fixed recommendation with an affiliate link attached to it.

Two Glock-specific notes:

• Steel-cased ammunition runs fine in a G17 in mechanical terms. The constraint is usually your range rather than your pistol, because many indoor ranges prohibit steel cases and bi-metal jackets outright. Check before you buy a case.
• 147 grain is where a tired recoil spring shows itself first. If a G17 that runs 115 grain flawlessly starts short-stroking on 147, the ammunition is not the problem. Glock specifies recoil spring assembly replacement on a round-count interval for a reason, and a full-size gun that has been shot hard is due.

This is where the barrel length pays off. Because 4.49 inches is the service-pistol standard, you do not need to hunt for a short-barrel load, and you should not buy one. Short-barrel loads are tuned to open at lower velocity, and driven fast from a full-size barrel they can over-expand and under-penetrate.

Buy the standard version of a load with a real testing record. Federal HST, Speer Gold Dot, Winchester Ranger and Hornady Critical Duty all appear in our catalog and all have published performance through the FBI protocol, which asks for roughly 12 to 18 inches of penetration in calibrated gelatin with reliable expansion through heavy clothing. In 124 grain, out of a G17, any of them is a defensible choice, and the differences between them are smaller than the difference a barrel length change would make.

Then verify it in your gun. Buy 100 rounds. Fire 50 through the pistol with the magazines you actually carry, including at least one slide-lock reload, because a magazine that feeds ball ammunition perfectly can still hang a wide-mouth hollow point on the feed ramp. A Glock 17 rarely fails this test. Run it anyway, because the cost of running it is one box of ammunition and the cost of skipping it is unbounded.

Keep the remaining 50 in the gun and in your spare magazines, and replace them yearly. Repeatedly chambering the same round sets the bullet back into the case over time, which raises pressure, and that is a real failure mode rather than an internet one.

Four things, in descending order of how much trouble they cause.

• Unjacketed lead bullets. Glock barrels use polygonal rifling, and Glock advises against unjacketed lead projectiles in factory barrels. Lead fouling builds in the shallow polygonal grooves rather than being cut away, and heavy fouling raises pressure. Plated and jacketed bullets are fine. If you want to shoot cast lead, fit a conventionally-rifled aftermarket barrel.
• +P+ ammunition. SAAMI standardizes 9mm at 35,000 psi and 9mm +P at 38,500 psi. It publishes no ceiling at all for +P+, which means there is no specification for a pistol to be rated against. Standard +P is not a problem in a G17. +P+ is a manufacturer question, and the answer will not be found on a forum.
• Anything that is not 9x19. See the first section. 9x18 Makarov and .380 ACP are separate cartridges.
• Reloads of unknown provenance. Commercially remanufactured ammunition from a known loader is a reasonable practice option. Someone else''s garage output is not, and it will also void the warranty.

Most "my Glock will not run this ammo" problems are not ammunition problems, and it is worth naming them so you do not spend money solving the wrong one.

Magazines. Factory Glock magazines are the baseline. Aftermarket magazines and, more often, aftermarket base plates and extended followers are a common source of feeding failures that get attributed to a particular load. If a problem appears with one magazine and not the others, you have found it.

Recoil spring assembly. The Gen 4 and Gen 5 dual recoil spring assembly is a wear item on a round-count schedule. A worn spring shows up first as failures to return to battery with the lightest-recoiling ammunition you own, which is usually a subsonic 147 grain load, and it looks exactly like an ammunition problem.

Limp wristing. A full-size 9mm is forgiving, but a loose grip absorbs the slide velocity the pistol needs to cycle. If failures follow the shooter rather than the gun, that is what happened.

Rule out all three before you conclude a pistol dislikes a load. Actual ammunition incompatibility in a Glock 17 is rare enough that it should be the last hypothesis, not the first.