Author Topic: What causes case bulge?  (Read 11003 times)

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Offline Wobbly

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Re: What causes case bulge?
« Reply #30 on: June 03, 2019, 08:25:11 AM »
I've really only had recent history with 223, and with those I insisted on BT (boat tail) bullets because of the ease of seating them without mishap. I don't suppose you're using BT bullets ?
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Offline Grendel

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Re: What causes case bulge?
« Reply #31 on: June 03, 2019, 09:01:20 AM »
No. As I'm loading for a lever action, these:

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Offline Ron Ia

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Re: What causes case bulge?
« Reply #32 on: June 03, 2019, 08:30:07 PM »
things to check wall thickness bullet outside measurement are you using a seating die then a crimp die your 9mm bullets should be .355 when setting up your seating die set your OAL first then do a light crimp after there's always great videos on YouTube that can help you out   

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Offline Wobbly

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Re: What causes case bulge?
« Reply #33 on: June 04, 2019, 12:57:48 PM »
No. As I'm loading for a lever action, these:



The problem is obvious. That bullet is WAY too big !!

 O0
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Offline recoilguy

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Re: What causes case bulge?
« Reply #34 on: June 04, 2019, 03:25:34 PM »
Your bullet is never to big for a gun...?.

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Offline redbaron

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Re: What causes case bulge?
« Reply #35 on: June 05, 2019, 06:38:12 PM »
So I think I've got the problem licked. I just loaded up 100 rounds today for a match this weekend and every round plunked in the case gauge perfectly. I think the biggest thing that helped was getting rid of the crap brass and readjusting my dies. Should be smooth sailing from here

Offline Wobbly

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Re: What causes case bulge?
« Reply #36 on: June 06, 2019, 04:16:11 PM »
I think the biggest thing that helped was getting rid of the crap brass and readjusting my dies.

To be clear, I think it was the cannelure in the case acting as a stress riser. The case was merely buckling at its weakest point.

I'd like to hear about that adjustment procedure. You mentioned changing the Sizing die as well as the Seating die and the Crimp die. Was it some, all, or just what ?

Also do you lube in any way ?
« Last Edit: June 06, 2019, 04:24:58 PM by Wobbly »
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Offline redbaron

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Re: What causes case bulge?
« Reply #37 on: June 06, 2019, 10:08:23 PM »
I had initially adjusted the seating and crimp die using a dummy round to get in the neighborhood and then fine tuned the adjustments from there. When I went back and readjusted those two dies I went by the instructions that came with them. It wasn't a big change in the die setting, but the dies were set different from using the dummy to using the instructions. I'm not really sure how much of a difference it made to the finished rounds.

The Aguila headstamps had the cannelure, but they weren't the only ones giving me problems. CBC, FC, military brass and a couple others were also giving me the same problems consistently, and none of them had a cannelure.

Edit: Oh and I don't normally use lube on pistol brass, but I do use OneShot on rifle brass
« Last Edit: June 07, 2019, 10:11:19 AM by redbaron »

Offline Wobbly

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Re: What causes case bulge?
« Reply #38 on: June 07, 2019, 10:11:59 AM »
Here's how I set dies...

? Sizing: I use a piece of paper as a feeler gauge between the shell holder and the die. At the top of the stroke (without a cartridge brass in place) I can withdraw the paper without tearing it. On a 550, the die holder normally has about 0.008" free play up/down. With 0.003" clearance you'll see the die holder rise at the top of the stroke, but the die holder will still wiggle freely.

This adjustment sizes the maximum amount of case, without injury to the super hard (and brittle) carbide.

? Seating: 1) The stem: You want to make sure the seating stem is not contacting the case mouth and thereby crushing the case.
2) The body: In Dillon dies I don't think any crimp is possible, but on other die brands you need to insure that the die body imparts zero crimp. This is a "screw down until touching and then back-off" adjustment.

? Taper Crimp: Read the article on Taper Crimp in the stickies. Press a sample bullet into a sample brass that has NOT been belled. Get that dimension so that you have a number to aim at. (Having a number to aim at is EXTREMELY important !) Then during production (with actual bullets in place), slowly move the TC die down until you achieve that number. It is usually in the 0.376 to 0.378" range, with lead you might see more, but it MUST be 0.379" or less.


Adding any kind of case lube REALLY helps. When I used a 550, I rolled every third case on a Lube Pad. Now with my 650 I lay several hundred cases on their side and spray them twice with Dillon Case Lube. The lube moves around in the dies and smooths out sizing and crimping in ways you can't imagine. The amount of lube is tiny, and the time it takes won't slow you down.

 ;)
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