Glock Gen 3 vs Gen 4 Pistols: What's The Difference?
Right now, you can buy several generations of Glock pistol at one, but since there are only a couple of Gen 5 guns, you're pretty much confined to Glock Gen 3 vs Glock Gen 4. Which is better? Well, better is very, very relative.
Glock makes some minor revisions every so often to their basic design, leading to a new "generation" about every 10 years or so. They weren't referred to as such until the Gen 4; the Glock Gen 3 guns were just called "Glock" pistols. The Gen 4 line, however, was explicitly referred to as Gen 4.
The differences are mostly cosmetic; no substantial changes really were made until the most recent of the Glock generations. However, the differences might be enough to sway you one way or another.
Glock Gen 3
At the moment, Glock is still selling the Glock Gen 3 pistols as well as Gen 4 and Gen 5. The Gen 3 pistols have been in production for 20 years. They are proven, without doubt, and truth be told don't really show their age from a certain perspective.
The Glock Generation 3 guns are very basic, in that they give you everything you need and nothing you don't. However, there are a couple of small extras that were thrown in over the previous generation.
Glock pistols of this generation added the finger grooves - some love 'em, some hate 'em - and the Universal Glock Rail to the dust cover of the frame. Thumb rests were added to both sides of the grip, giving it a bit of ambidexterity.
Glock also changed the extractor so that it would stick out when the gun was loaded, thereby acting as a loaded chamber indicator. An additional cross pin was added above the trigger guard pin, acting as a fence for the barrel link when the gun recoils.
Everything else remained the same, and in fact remained the same going into the Glock Gen 4 guns. The Gen 3 guns, much like the first two generations, are workhorse pistols. They digest most ammo well, shoot easily enough and more than accurately enough for government work, and so on.
Glock Gen 4
Glock Gen 4 improvements weren't nothing, but didn't exactly reinvent the wheel. However, there's just enough of a difference that it could definitely tilt you to one side or another if deciding between a Glock Gen 3 vs Glock Gen 4 pistol.
Right before the introduction of the Glock Generation 4 guns, a limited edition of Gen 3 pistols was made - called the RTF2 or "Rough Textured Finish" - with a few different bits. The slide serrations were changed to fish scales and the texturing was changed, with stipling rather than a rough texture on the sides and checkering on the front and back of the grip.
The last bit was popular, as the RTF2 stipling was made standard across the whole Gen 4 Glock line. They made the magazine release button a little bigger and made it swappable for left-handed users. The recoil spring was changed to a dual captive unit instead of a single captive spring.
Glock also created modular backstraps for the Gen 4 pistols, which were cleverly named the "Glock Modular Backstraps."
Along with all the standard models such as the Glock 19 Gen 4, the fourth generation of Glock pistols also introduced the Glock 43. While completely and utterly late to the single-stack subcompact 9mm party, it still became one of their most popular pistols to date.
Gen 4 Glocks Are LE Only
After Glock released the Gen 5 pistols - which had a suite of significant updates including new slides, frames, barrels and more - the Gen 4 models were switched to LE sales only. Glock does not sell them to the consumer market; they are only sold to police departments and federal agencies.
Unless you're a police officer, you can't buy one!
New, that is. However, a lot of Gen 4 guns will be in and out of police trade-in inventory at various dealers, shops and so forth on the used market. You might find some NIB guns, and you might find some gently used ones. Even if you get a used gun, it's still a Glock. Even if it's beat up, you can still rebuild it by replacing all the internal parts and get years of use out of it.
Glock Gen 4 vs Glock Gen 3 Mostly Comes Down To Feel
As you've gathered so far, the differences between Glock Gen 4 vs Glock Gen 3 are moderate. Nothing is changed internally or really all that substantially; the gun is pretty much the same except for some surface changes. That said, those surface changes may make a difference to you.
The stipling on the Gen 4 Glock pistols is a little more aggressive. You'll get a bit more secure of a grip. Granted, some people don't like that as much; some pistols feel almost like the gun could double as a low-grade rasp and that's annoying. (1911 grips, am I right?) However, some prefer the added traction, especially when shooting with gloves.
Another feature that the Glock Gen 3 guns lack is the modular backstraps. It either fits you or it doesn't and there's not much to help it if that's the case short of an aftermarket frame. The Gen 4, on the other hand, has several sizes of backstrap that can be easily swapped in for a better fit. That's a plus if the standard pistol doesn't have the best fit out of the gate.
There is also the reversible magazine catch for lefties, which is a plus. A dual recoil spring can slightly change the recoil impulse, but only so much.
You'll have to get out and handle both. Shoot both if possible. That will tell you which to get. The thing about Glock Gen 3 vs Glock Gen 4 is the guns are almost identical; it's just that the latter has a few more bits of kit than the latter, and at that not a heck of a lot. Whether they matter enough to spend a little more for the Gen 4...is up to you.