This picture shows factory ported Glock pistols. The two most common are the C model pistols which you can see int he photo above as the one on the bottom. The other two are somewhat uncommon. The Glock on the top is a Gen 1 Glock 17L with an optional factory three port barrel. The middle Glock is a Gen 3 Glock 24C with 4 ported barrel. Somewhat similar to the Glock 18C porting like this one below.

Photo courtesy of DJ Niner from



  • DIR911911 .

    are those 4 port versions really worth it considering they HAVE to suffer a velocity loss of at least 150-200fps considering how soon the ports start and how many there are.

    • Jake

      cut them a break, 9mm is a dang wrist twister 🙂

    • Nicholas C

      Depends on the load. Many open division shooters shoot 9mm major for the increase in pressure which makes the comps work better.

    • Anonymoose

      Magnaports have been tested for decades and found no or negligible velocity loss.

      • DIR911911 .

        magnaporting is done at the end of the barrel , not 1/2 inch from the chamber.

        • iksnilol

          Glock factory porting is also close to the muzzle.

    • Andrew c

      Someone did a chron test between ported and non ported flicks. 10-15 fps

    • iksnilol

      not really that much, otherwise revolvers would be useless.

      • DIR911911 .

        you think a cylinder gap is the same as 4 big holes cut in the top of a barrel? you’re not worth talking to.

        • iksnilol


  • USMC03Vet

    The equivalent of putting a wing on a Honda Civic.

    • TheNotoriousIUD

      Not if you have NOS bro.

    • iksnilol

      Funny enough, improving aerodynamics helps even the “inferior” FWD cars.

    • SerArthurDayne

      With Type-R stickers son.

  • T Rex

    In the interest of educating those who might be unaware, compensated/ported semi-auto pistols are not really meant for or well suited in defensive carry applications since the huge ball of fire flash directed upward from the top of the barrel/slide greatly compromises a shooters night vision if needed in a low light or after dark self defense scenario. Using a compensated/ported semi-auto pistols is generally only practical in competitive speed shooting or similar applications.

    • HSR47

      I’m going to call BS on this.

      Have you ever shot ported and non-ported versions of the same gun at night with both defensive and target ammo?

      No? Because I have.

      In terms of impact on night vision, the amount of flash that you see is roughly the same between the two when using the same ammo; The chief difference is where that flash is localized.

      In the case of a bare muzzle, that flash shows up to the shooter as a circle (it’s actually more of a toroid) radiating from the muzzle perpendicular to the flight of the bullet. In other words, you get a fireball that puts a spot on your vision that obscures a significant area directly around the sights you should have been using when you pulled the trigger.

      With most factory-ported guns, you get a similar amount of overall flash, but the vast majority of it is localized in the gas leaving the ports, which in turn means that it generally does LESS to put spots in the way of your sights.

      Frankly, the BIGGER difference comes from comparing loads using standard powders with loads using low-flash powders. If you’re worried about muzzle flash destroying your night vision, you should make sure to carry ammo that uses a low-flash powder.

      • T Rex

        You’re just flat out wrong H. Anyone who has actually tried a Glock 17C or 22C in low light training knows you simply don’t know WTF you’re talking about. As far as “low-flash” powder, most of the major ammunition manufacturers who want to be competitive in the LE duty ammo market use a powder with relatively low flash. Using the duty/practice ammo combo of Speer Gold Dot and Speer Lawman in 9mm, 40 S&W, or 357 Sig as an examples, the muzzle flash in all of those Speer products is acceptably small and brief enough to not significantly affect the shooters night vision when shot from a non compensated pistol, but all emit a giant flame from the top of any “C” Glock. If there really were such a thing as commercially viable duty ammo that didn’t emit a giant night vision killing flash from the top of a compensated/ported pistol, most of LE would be carrying the 17C or 22C today; the reason they don’t and never will is because LE trainers discovered shortly after the “C” Glocks hit the market in the mid to late 90’s that compensated pistols were not suitable for duty use because they can adversely affect a shooters night vision in low light scenarios.

        • HSR47

          Again, you’re using an appeal to authority, but not relating any personal experience with the sort of porting that they’re actually using today (well, the style that they’re using on everything but the G18C, but that doesn’t really count).

          If you look at the photo, you’ll see that Glock has substantially changed how and where they port their pistols. The porting style that uses cuts perpendicular to the bore across the 12 o’clock is their original commercial style, and is undoubtedly what the “reports” you’re referring to are based on. That WOULD make sure that the flash was localized virtually entirely in the middle of the sight plane.

          The style that has two cuts parallel to the bore at roughly 10 o’clock and 2 o’clock is significantly more recent, and is the general style of porting that I have personal experience with. This style of porting leaves the majority of the center of the sight plane, including the sights themselves, virtually free of flash. Again, I have actually shot a pistol with this type of porting in low-light conditions side by side with a non-ported variant of the same gun. Have you ever done something similar?

          There is a HUGE difference between the two styles of porting, and the continued insistence that “ported guns are always bad at night” is the equivalent of insisting that all sedans with diesel engines suck because the VW Rabbit from the 1980s sucked. Technologies and techniques change and improve over time, don’t insist that the state of the art yesterday will always remain so.

    • gunsandrockets

      So by the same logic all revolvers are not well suited for defensive carry?

      • T Rex

        Guns you’re obviously unaware that any revolver firing any type of ammunition potent enough for effective duty/defensive use (357 magnum for example) emits a significantly large flash from burning gases escaping from the gap between the cylinder and the forcing cone; so any additional giant flash emitted from a ported revolver barrel is pretty much a moot point. Any healthy revolver load will flash a healthy sized ball of flame from the front end of the gun whether compensated or not.

        Of course anyone who doesn’t know what it is like to actually shoot a night course with a duty type revolver such as a 4″ Mod 586 S&W, wouldn’t know that any non compensated semi-auto duty type pistol such as a Glock 22 or Sig P226 firing duty suitable ammunition has negligible muzzle flash when compared to the old revolvers LE used to carry, which is just one of several reasons LE “duty” revolvers are now obsolete.

        • gunsandrockets

          Unaware? That’s funny seeing as walked right into the logical trap I set for you.

          • T Rex

            Ok I get it, instead of unaware you’re just not smart enough to recognize that in low light a giant ball of fire flashing two feet from the shooters eyes is detrimental to their ability to reacquire the sights or the target regardless of whether the giant ball of fire originates from a revolver or a compensated pistol.

          • HSR47

            The point that he and I are making is that you’re using magical thinking.

            Shooting ammo out of a ported barrel doesn’t cause it to magically produce more flash; it produces the same amount of flash that it would from a non-ported barrel. The only difference is where that flash is localized.

            Barrels ported at 10 and 2 tend to cause the flash to localize there, which in turn vastly reduces the degree to which you get flash from the muzzle after the barrel uncorks, and leaves your sight plane virtually free of flash: There’s flash all around the sight plane, but not in it. This leaves you free to actually see what you’re shooting at, more so than you would without porting, and with a bare muzzle.

          • Shawn Shahan

            I carry a 23c every day as my duty weapon, and every time we requalify we have to fire in low light. I have specifically tried to see the giant fireball everyone (that doesn’t shoot a compensated pistol) complains about. Guess what, it’s no more blinding than any other pistol I have shot in low light, so unless you have shot one stop with the bull***t.

  • bobby_b

    Cut me some technical slack here for the dumb question, but isn’t porting just used to cut down on recoil? Is there some other benefit from it?

    • GearHeadTony

      Technically, “recoil” is the rearward movement of a firearm after firing. Barrel porting acts against the upward “muzzle flip” which results from the barrel being above the axis of your arm. To my knowledge, there is no other purpose for barrel porting. It does have some other effects that are generally considered negative effects for real-world applications.

  • John

    Interesting aside. You can see three distinct finishes.
    The 24C has the “Teflon” finish, most desired but the earlier real Tenifer, are the most durable….

  • ??

    Instant sight blackener.

  • DJ9r

    With the two-port factory-ported Glocks, I’ve measured G19 and G19C 9mm pistols side-by-side and got a difference of from 21 to 35 FPS (average). However, when you take the normal velocity spread of a single pistol and load into account, it’s not unusual for one or more of the highest individual velocities from the G19C to be faster than the slowest velocities from the G19 (these were 10-shot strings). Based on that info, I just can’t get too worked-up about it.

    I never did any chronographing of my 4-port G24C, as I didn’t own it for very long (the accuracy of that particular individual pistol sucked pretty badly).