Light primer strikes Gen2 G20

Discussion in 'The 10 Ring' started by misfit356tsw, Apr 14, 2013.

  1. Purchased a used Glock 20 Gen2 with a WL prefix. Got some Underwood ammo and went to shoot it for the second time and it was not firing due to light light primer strikes 10% of the time. The primers barely had a dimple in them. Looked at the trigger bar and it is a 4256 with quite a bit of wear. This gun also has the black 4340 ejector. Looks like I have some work to do. :supergrin:

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    #1 misfit356tsw, Apr 14, 2013
    Last edited: Apr 14, 2013
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  3. That might have been god's way of saving your eyes, hands & gun. The GEN 2 G20 barrels have a reputation of a significantly less supported chamber. Depending on which load you bought, it might not be the best idea to run it through a stock GEN 2 G20 barrel.

    About the light strikes, it could be something as simple as a gummed up firing pin channel. Detail strip the slide, clean out the FP channel & inspect the striker assembly.

    Of course it's possible that the ammo is to blame, so try contacting Underwood to see if they can help.


    #2 Meathead9, Apr 14, 2013
    Last edited: Apr 14, 2013
  4. Thank you for the concern about the barrel but there is absolutely no signs of overpressure, smiles, etc. There is barely a bulge in the brass. I reload, so I check 10mm brass with an extra eye. I was worried about that myself.

    I detail stripped this gun prior to shooting it, as I am terribly obsessive. Brought the gun home after shooting today and made sure that I had reassembled the striker properly.

    It is possible that ammo is to blame but these strikes were nothing more than small dimples, leading me to believe it was not an ammo issue.

    The portion of the trigger assembly that the striker rides on has seen better days. This on top of the fact that it has now been replaced by a 4256-1 model.

    Thank you very much for your input. I will try cleaning the FP channel again tomorrow. You have a great night. :wavey:
  5. And just so everyone knows, this gun is all stock.
  6. bentbiker

    bentbiker NRA Member

    Was the dimple in cases that fired also light? Can someone advise as to whether Underwood is known to have hard primers? In this time of scarce primers, maybe they had to buy whatever they could find???

    Since you don't know what striker spring is in the gun, you might consider replacing with either the std spring or a 6# extra strength spring.
    #5 bentbiker, Apr 14, 2013
    Last edited: Apr 14, 2013
  7. The dimples in the cases that fired looked like normal strikes on the primer. I will probably be replacing the striker spring as an extra precautionary measure. Thank you sir.
  8. Opie 1 Kenopie

    Opie 1 Kenopie Regular Guy

    You gotta flick your wrist when you fire each round like they did in old movies. It gives the firing pin that extra oomph.


    Pics would help
  10. My Gen 2 G20 lacked chamber support and could not hande Underwood, DT, etc. However, it cycled everything else fine. I installed an aftermarket barrel with a heavier spring and have been blasting away ever since. Sounds like you have a handle on it but be barrel was sloppy and got lucky.
  11. Taterhead

    Taterhead Counting Beans

    I agree with checking the firing pin channel. I like to clean with a Qtip and rubbing alcohol. Just be sure not to leave any Qtip fuzz. The second look would be the striker spring.
  12. MrGlock21

    MrGlock21 NRA Instructor

    And yet that Gen2 barrel is strong enough to shoot the hottest factory ammo available. I was there in the early nineties and owned 3 Glock 20 all of which digested the hot Hirtenberger ammo without issues.
    I observed one pistol being blown up with a double reload of 3N37 and when the whole mess was sent to Glock for examination it was found that the barrel was still sound and intact.

    OP, I had the same issues with one of them. Clean it thoroughly. If it still acts up get a red or blue firing pin spring!
    #11 MrGlock21, Apr 16, 2013
    Last edited: Apr 16, 2013
  13. I had a similar issue with my own reloads. The round headspaces on the mouth of the round. When I correctly tapercrimped the round to .423, my light primer strikes went away. Still, you've got factory ammo ....... and I wouldn't expect you to have this problem.
    Just FYI ....
  14. IMG_4983.jpg
    This is a picture I found that illustrates the difference between the 4256 and 4256-1. I will be replacing the 4256 trigger bar with the replacement 4256-1 because the longer cruciform will pull the striker back farther, ensuring proper ignition. This on top of the fact that the top of the cruciform in my pistol is well worn. I will also be replacing the striker spring since I do not actually know how old it is.

    Checked the striker channel and it is still clean, as I cleaned everything before I shot the gun.
  15. Taterhead

    Taterhead Counting Beans

    Good plan. Glock parts are inexpensive and easy to swap. Let us know if that solves the problem.
  16. I will keep that in mind when reloading. I haven't started with 10mm yet because it is currently fairly difficult to find any of the supplies. Just keeping my brass for now. Thank you.

  17. If you use a set of dial calipers on factory ammunition, I think you'll see that their taper crimp is closer to .422 .... So, that's what I do.
  18. Finally got around to testing my Gen2 G20 that was having light primer strike issues with the original 4256 trigger assembly. The new 4256-1 assembly has fixed the light primer strike issues. Looking at the old assembly it looks like the cruciform (where it makes contact with the striker) was worn to an almost knifelike edge. This compounded with the fact that the old cruciform was shorter, thereby not pulling the striker back as far, probably caused the perfect storm creating my issues. Thank you everyone for your input on this subject and I hope this helps someone in the future.

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