Glock Bulge By The Numbers

The #1 community for Gun Owners of the Gulf Coast States

Member Benefits:

  • Fewer Ads!
  • Discuss all aspects of firearm ownership
  • Discuss anti-gun legislation
  • Buy, sell, and trade in the classified section
  • Chat with Local gun shops, ranges, trainers & other businesses
  • Discover free outdoor shooting areas
  • View up to date on firearm-related events
  • Share photos & video with other members
  • ...and so much more!
  • ABlaster

    Marksman
    Rating - 0%
    0   0   0
    Joined
    Dec 2, 2022
    Messages
    615
    Points
    93
    Location
    Tallahassee
    Per a member's request, I am sharing my first-hand experience with the "Glock Bulge." This case was fired in a Gen 4 Glock 35. I measured the bulge with calipers before and after, and the result was .007 inches difference. Not a lot to look at on paper, but you can see it without magnification and it can mean the difference between chambering in a traditional chamber or not, as happened to me. It was beating the gun open after a bulged case locked up my STI that hurt my hand enough to keep me out of practice for a few days, so it's a hard lock! The left photo is after being pushed through a Redding GRX die and the right one is the "before" photo.
     

    Attachments

    • IMG_5857.jpg
      IMG_5857.jpg
      51.6 KB · Views: 66
    • IMG_5856.jpg
      IMG_5856.jpg
      58.5 KB · Views: 69
    • Like
    Reactions: FLT

    Rebel_Rider1969

    Well Known Nuisance
    Rating - 100%
    35   0   0
    Joined
    Sep 12, 2019
    Messages
    19,772
    Points
    113
    Location
    Range, Al. Near Brewton.
    Be dammed if I can see it. On the bottom, middle or top?? Luckly I have a case gauge for 10mm. I must not be getting any?? G20. TNW Areo carbine. ** well duh. I lube and put em thru the sizing die. I'll have to look at my spent shells.
     

    ABlaster

    Marksman
    Rating - 0%
    0   0   0
    Joined
    Dec 2, 2022
    Messages
    615
    Points
    93
    Location
    Tallahassee
    It's about a fifth of the way up from the bottom of the case on the right. If you look at the left photo the shiny parts are where the push-through die made contact to give you some context.
     

    ABlaster

    Marksman
    Rating - 0%
    0   0   0
    Joined
    Dec 2, 2022
    Messages
    615
    Points
    93
    Location
    Tallahassee
    I might be imagining it, but I can see it in the photo. Of course I know where to look! It’s only a .007” difference so it might not show up very well and I have crappy photography skills.
     

    Rebel_Rider1969

    Well Known Nuisance
    Rating - 100%
    35   0   0
    Joined
    Sep 12, 2019
    Messages
    19,772
    Points
    113
    Location
    Range, Al. Near Brewton.
    I might be imagining it, but I can see it in the photo. Of course I know where to look! It’s only a .007” difference so it might not show up very well and I have crappy photography skills.
    So if you placed it in a check gauge it would not slide in. Got the gist of it. So even with an aftermarket barrel it still does it? Seems crazy.
     

    ABlaster

    Marksman
    Rating - 0%
    0   0   0
    Joined
    Dec 2, 2022
    Messages
    615
    Points
    93
    Location
    Tallahassee
    I haven’t tested the brass from the STI yet. I keep about 2,000 pieces of brass in rotation at any given time so it takes a bit to process it all.

    Based on initial inspection, I anticipate being able to ditch the de-bulging process for practice ammo. Like I said, I can see the bulge and the STI brass doesn’t have it. I bought about 4,000 rounds of factory match ammo last month so my usual “do every process available” for match stuff won’t apply either.
     

    Midnight son

    Expert
    Rating - 100%
    1   0   0
    Joined
    Nov 5, 2012
    Messages
    465
    Points
    43
    If you load/shoot with a glock or reload range pick up brass, "bulge busting" with a push through die will always be a necessary step with the .40 imo. I have a cheap Lee bulge buster that has worked great......I always keep a coffee can full of busted brass so not to worry about it when I want to load a thousand.

    Does the glock 10mm leave a portion of the case unsupported too?
     

    ABlaster

    Marksman
    Rating - 0%
    0   0   0
    Joined
    Dec 2, 2022
    Messages
    615
    Points
    93
    Location
    Tallahassee
    As long as the brass was going back in my Glock it wasn’t necessary. I always did it with match ammo just in case, but my practice fodder didn’t get the same level of care.

    Like you said, I always run range pick up brass through it before loading it the first time!

    I have zero experience with the 10mm Glocks, so maybe someone will come along!
     

    ABlaster

    Marksman
    Rating - 0%
    0   0   0
    Joined
    Dec 2, 2022
    Messages
    615
    Points
    93
    Location
    Tallahassee
    RR69, this is a loaded round that has the bulge attempting to go in a check die.
     

    Attachments

    • FCE4B5D2-0378-466C-9441-CC3AEC364BA3.jpeg
      FCE4B5D2-0378-466C-9441-CC3AEC364BA3.jpeg
      225.2 KB · Views: 44
    Top Bottom