Glock Bulge By The Numbers

[ABlaster]

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.

 

[Rebel_Rider1969]

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]

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.

 

[Rebel_Rider1969]

Is it in line with the extractor mark on the rim?

 

[ABlaster]

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]

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]

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.

 

[Rebel_Rider1969]

Seems like glock should "flute" the chamber. I wonder why they dont?
Fyi, the g44 .22 is fluted...duh.

 

[Midnight son]

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]

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]

RR69, this is a loaded round that has the bulge attempting to go in a check die.

 

[Rebel_Rider1969]

RR69, this is a loaded round that has the bulge attempting to go in a check die.

Ok, yeah, i have one from wilson i use to check my handloads. I need to try some of my spents. Fyi you'd be suprised at the factory made rounds that won't go in....