Bulged Cases

[garyb]

I have a PM40 which has performed flawlessly...never an FTE nor a FTF.... That is until recently. But fortunately I found the problem. During my routine tactics training with a friend of mine who is a retired master instructor for LE, I had a couple of FTF's with reloads. The jams were so hard that it was very difficult to manually eject the partially chambered round. My first reaction was shock and embarrassment. After all, my buddy is a die hard Glock man and this was a Kahr I was shooting. When he ejected the round, he slid it in his Glock and said, "See...a Glock eats everything".

I went home and to analyze the situation. I removed my barrel and placed each reloaded round into the chamber to see what I could find. During analysis of 100 rounds, I found that I had 5 which would not go into the chamber all the way. I looked at the each round more carefully and found the casings were bulged at the body, just above the head (extraction groove). I had always only reloaded my own casings but these were casing I had picked up at the range which were co-mingled with my buddies casings, which I reloaded for myself. Never again. I am going back to only reloading my own casings. This could be a dangerous situation involving pressure.

From now on I will either mic the casings of my reloads or perform a simple check for casing bulge by removing my barrel and placing each reloaded round in the chamber, to be certain it slides in easily.

Lesson learned.

[OldLincoln]

I think the Lee crimping die sizes the outside of the case including the bulges. I'd be leery of shooting bulged reloads in a 40, especially a Glock which has a history of problems with that exact scenario. In the Glock .40, the chamber is lacking support above the ramp and cases have been known to blow out in the space between the rim and the chamber.

[getsome]

Hi garyb, I am curious about this...If you screw in the resizer die all the way to the shell holder wouldn't it remove the case bulge?...I have heard that when you see this in an empty case it was most probably fired in a Glock pistol since that design doesn't fully support the case at the rim and explains why it would go back in your friends Glock and hung up in your Kahr...

I try to only pick up my brass at the range and before I start shooting I will sweep the lane and all the way back to the rear wall but even doing that I sometimes still pick up some other caliber brass or a strange brand of case which I throw out...

I hope some more experienced reloaders will add their opinion as to why your die didnt remove the case head bulge....I have only been reloading for a couple of years but feel pretty comfortable with it now but still learn something new from time to time like the post below titled "Leason Learned"...

One other thing I have noticed is that brass is not just ejected from my PM40 it is hurled rearward and becomes a projectile and when my son is shooting it I stand way off to the side due to being beamed in the forehead a few times that smarted and drew blood...

I also noticed the brass from the PM40 has a big dent about middle of the case from hitting the ejection port I guess and the brass from my M&P .40 doesn't have this dent...It doesn't seem to hurt anything but it does show the extreme velocity and slide speed the PM40 pistol has...

[MW surveyor]

garyb, I'll bet those 40s were shot out of a Glock! Next time you pick one up that you haven't de-primed, look at the primer. Those Glock firing pins leave a distinctive mark.

[Ikeo74]

Youe problem may be caused by your own die adjustments. This can occur by either over crimpimg the bullets or by your seating die set to low crushing the case some. the reason it shows on range pickups could be because some cases are slightly streched. Longer cases will crush in a normal die adjustment if it was set for the shorter ones.

[garyb]

Youe problem may be caused by your own die adjustments. This can occur by either over crimpimg the bullets or by your seating die set to low crushing the case some. the reason it shows on range pickups could be because some cases are slightly streched. Longer cases will crush in a normal die adjustment if it was set for the shorter ones.
I have not seen this in the casings I have fired and reloaded in my PM40. Only in cases I've picked up at the range....and like some folks above had stated, were previously fired from a Glock. My buddy is a Glock man and I'd bet they were his cases. We are going to see if they fire in his Glock during our next training session (after deer season ends). However, it could also be longer cases crushed in normal die adjustment, as you stated, but these were not from my cases. Anyway, since sorting out the bad/bulged cases and using the chamber check system I implemented, I have completely solved this problem without needing to change my die adjustments. The dies which seem just fine for my own cases (fired from my PM40). I think I will leave well enough alone for now. Thanks for the input.

[nksmfamjp]

When you pick up brass, you really have to sorrt it well. I don't know why but some Glock bulges are so extreme that I worry about the inteegrity of the cases. Most are just a small bump and I load those. for me, I just rely on my brass sorting experience.


. . .and I ask. . .Why does Glock not fix their design!

[SGV]

When you pick up brass, you really have to sorrt it well. I don't know why but some Glock bulges are so extreme that I worry about the inteegrity of the cases. Most are just a small bump and I load those. for me, I just rely on my brass sorting experience.


. . .and I ask. . .Why does Glock not fix their design!

They did, a long time ago. In the 3rd Gen pistols the chamber dimensions were tighted. If you look on the barrel hood of a Glock you'll see a little pentagon "Proof" stamp. If there is a dot in the middle of the pentagon, it's the tighter chamber.

[CJB]

I looked at the each round more carefully and found the casings were bulged at the body, just above the head (extraction groove). I had always only reloaded my own casings but these were casing I had picked up at the range which were co-mingled with my buddies casings, which I reloaded for myself. Never again. I am going back to only reloading my own casings. This could be a dangerous situation involving pressure.


This is an old problem. When I was reloading commerically in the 80's and 90's, it was a problem, and a problem before that. My own experience is with figuring out how to get the 9mm's to chamber, even after being "fully sized", but the same is true on 40's, and 10's. The 45's are much lower pressure and usually dont have an issue.

There are two things that happen. First, as you noted, bulging from being unsupported at the head/feedramp area. The other problem is migration of brass toward the head during multiple sizing operations from continued reloading. The tapered 9mm seems to suffer most from the flow of material rearward, while straight walled 40's and 10's are less prone (but not immune) to the condition.

Here's what you'll find. Take a look at your resizing die. Most resizing dies have a very generous rolled lead-in to the actual sizing diameter. They do that to make feeding into the die easy, especially so on auto or semi-auto reloading machines. That is also the downfall of the sizing operation, because you cannot size the corresponding area on the case. Couple that with sometimes VERY thick shell holders, and you get the thickness of the shell holder lip, plus the thickness of the lead-in on the die which remains totally untouched by the resizing surface.

My solution was to move the 9mm's from AmmoCrafter to Dillon machines, rework the sizing die by diamond grinding the carbide insert shorter, thus eliminating about half of the lead-in taper, and reworking the already good Dillon shellplate to make it a little thinner (using a surface grinder). After that we had a lot better results resizing lumpy 9mm cases.

And... the change from AmmoCrafter to Dillon was due to the straight inline design of the AmmoCrafter, opposed to the rotary design of the Dillon. Something with the AmmoCrafter... I couldn't get a good insertion into the reworked die, but the Dillon ate it up for breakfast.

If your die is "correctly" seated, and you still have problems (you may), find a local machine shop that will use a diamond wheel on their surface grinder to take about half the taper out... just remove material from the bottom of the die. If you're using a shell holder, have them take about 1/3 of the lip off. Shell plate... I'd try first, many of those are thin lipped already.

The cost on that rework should be minimal - if you got friendly with the guys it might be a couple of sixpacks. If not - oh... twenty ought to cover it in these parts of the swamp.

[Tilos]

An old thread but wanted to add that a simple mark across the case haed and primer will identify your reloads on the ground or floor.
If it don't have your mark...leave it there.
When they go into the tumbler check again for your mark and toss those without it...or give them to your glock buddy.
Tilos

[U.S. Patriot]

Brass fired out of a .40 Glock will be buldged. Do to the unsuported chamber. Unless you know what you are doing, stay away from it.

[94zcar]

Lee Makes a die to get rid of the Glock bulge, It's called the bulge buster.
http://leeprecision.com/case-conditioning-tools/lee-bulge-buster-kit/