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Glock 27 3rd vs 4th gen - What parts are different?

Discussion in 'General Glocking' started by Tech knight, Jan 11, 2013.

  1. Tech knight

    Tech knight

    Aug 20, 2010
    What parts are different internally and should I get a 3rd or 4th gen?

    Do both have the same reliability using a .40 S&W to 9mm conversion barrel?

    Without any of the grip plates the 4th gen is a tiny bit smaller diameter then the 3rd gen?
    Last edited: Jan 11, 2013
  2. SiGlockBoy


    Mar 4, 2009
    Both are similar. Small hands like the stock Gen4 better than the 3. In my hands, short fingers like sausages. I can touch the thumb and middle finger while gripping the gen 4. The Gen3 leaves me with a 1/8th" gap between thumb and middle finger while gripped. That equates to a gun less rotated in my hand and more in line with arm for the Gen 4. Feels much nicer even though just a couple mm circumference difference.

    As for parts, Visual inspection lends me to see the mag release is bigger and farther rearward. Grip and adapters. Texture on grips. Mags with extra release detent for ambi setup. Could be more, but those were the obvious without comparing part numbers.

  3. SiGlockBoy


    Mar 4, 2009
    I've looked closer. Hope it still helps even though not timely.

    Ejector is twisted and not so bent on the 4 vs 3 as well as the housing is different due to grip I suspect.

    Trigger bar is different in that the 4 has the dimple on the FP safety cam. 3 has no dimple.

    Barrel caming lug is different on 4 as it appears to be shorter/ longer between 2. Easily seen with both barrels upside down next to each other. Sorry no pics. I expect due to more case support on 4 barrel chamber.

    Also noticed on 4 that it is very steppy going into battery in the last 1/4" of travel Gen 3 very smooth and deliberate. 4 seems to stick a bit and then pop into battery. Sometimes hangs out of battery if done very slowly. Brought concerns to customer.