Bulging .40 cases

NJM15 · May 13, 2017

Recently I have noticed some bulging about 3/16" above the rim
I am using starting loads , 155 gr Extreme lead, usually power pistol, stock barrel.
I have found bulges on range brass fired by early gen Glocks but never noticed it on my fired rounds. the only thing I can think of is having too tight crimps increasing the pressure.
any other ideas ?
thanks

torizus · May 13, 2017

I believe that the case bulge issue is determined by the barrel. The chamber specifically, as the early glocks had an unsupported chamber. The case head was open/exposed on its lower half and would bulge from the pressure.

Which glock model are you using? From what I see, barrels are plentiful for those glocks.

scooter123 · May 13, 2017

More information would be very helpful.

Because you are using lead bullets I can only assume that you aren't shooting these reloads in a Glock. Because Glock has a widespread reputation for leading severely with lead bullet due to the use of octagonal rifling. If you are using these in a Glock plan on about 12-24 hours to clean the leading out of your barrel and do not shoot this pistol anymore until you have that barrel perfectly clean.

Second, if you are using the Speer #8 load manual stop using it. The #8 manual has a reputation for having many loads over pressure. Personally I prefer to use at least 3 sources of load data when working up a new load and usually go with the lowest starting load of the 3 for my first samples.

Finally double check the charge weight and overall length that you are using are actually correct. Because sometimes we can see something that actually isn't what was printed, especially if you have a tendency for dyslexia.

As for "overcrimping" a lead bullet in a brass case, I do not think that is at all possible with the taper crimp typical to the 40 caliber. However if you do crimp the case too small you could have an improper headspacing issue where the case is actually going past the headspace ledge in the chamber and you are "pinching" the case neck in the rifling. I would expect that if this is what is happening a close examination of the top of the case will show "scars" left by the rifling in your barrel.

427mach1 · May 13, 2017

Check your chamber dimensions. My 4013TSW has a fairly loose chamber and the fired brass bulges out slightly above the rim. I had the barrel replaced one time on S&W's dime and the new chamber was just as loose. I ordered a new one online and it came with the same chamber dimensions as the first two. I just run the bulged brass through my reloading dies and don't worry about it. My loads tend to be slightly above mid-range powder charges. Believe it or not, my Ruger KP944 has a much tighter chamber and I don't get any bulging.

muddocktor · May 13, 2017

scooter123, the .40 S&W wasn't even a dream in someone's eye when Speer #8 was published, so your warning doesn't hold, man.

As for your problem, NJM15, I don't know why you are suddenly experiencing this problem. I take it that you have been loading for this pistol you are suddenly seeing this problem with for a while and all of a sudden you are seeing bulged brass with lower power loads, right? Have you been shooting Power Pistol with other bullets with no problems in this pistol? I don't think a taper crimp could cause bulged brass; headspace issues yes but not bulged brass.

One thing you could look at is to get a Lee Bulge Buster and run your 40 brass through it before reloading. Maybe the brass you are using already has a certain amount of bulge and it's just showing more now. I wish I could help more, but I don't own a 40 or reload for them either.

bigedp51 · May 13, 2017

The Glock bulge occurs because the feed ramp extends too deep into the chamber like below. Glock fixed the feed ramp problem and the manufactures made the cases thicker.

If your bulge is around the entire base of the case you might have a large diameter chamber. Or thinner cases with a base diameter at minimum SAAMI diameter.

I have Gen 3 Glock 17 and Glock 22 and do not have any bulge problems.

We need more info on what pistol, your bullets and load.

STORMINORMAN · May 13, 2017

Bulge on the left would render that case 100% UN-RELOADABLE...

...IMHO! Never have I ever seen any case that BAD!

noylj · May 13, 2017

Crimp isn't the issue, unless, as stated above, you are crimping so severely that the case mouth is actually entering the throat.
However, that being said, stop thinking that the taper crimp holds the bullet—it doesn't. It is really just to get rid of the case mouth flare.
Check out some factory rounds and you'll find there is really no crimp—just a straight case.
Finally, a starting load in one manual can be over max in another. Don't think that your lot of powder is the same as the test lot, or that your bullets are the same. Since the gun you are using, the cases you are using, the primers you are using, and the lot of powder differ, you can not possibly get the same results.
Check at least two manuals and start with the lowest start load.
From my manuals, I show that for 155gn lead bullets, start loads with Power Pistol range from 6.1-6.7gn and MAX loads range from 6.7-7.0gn.
From my own testing in my guns, I found 5.4gn of PP to be quite accurate with 155gn bullets. With a different lot of powder and other components, this might be too light to cycle a gun without a change in springs—but it works great in my two Paras and EAA Elite.

BLUEDOT37 · May 14, 2017

NJM15 said:
Recently I have noticed some bulging about 3/16" above the rim I am using starting loads , 155 gr Extreme lead, usually power pistol, stock barrel.

the only thing I can think of is having too tight crimps increasing the pressure. any other ideas ?

You didn't say what pistol this is in?

You didn't give us any details on your load either?

What COAL" are they loaded to? Some pistols have very little (chamber) leade & if you didn't do a "plunk test" to verify the bullet's not being jammed into the rifling, once chambered, I'd check that.

I'd suspect that being an issue before I'd suspect the taper crimp with a lead bullet.

.

NJM15 · May 14, 2017

Sorry,
forgot to say I am shooting a S&W M&P 40
I have the Lee .40 bulge buster and never felt much
resistance pushing one through as I have recently.
I have a storm lake ported barrel I will try next time to eliminate that possibility

Wee Hooker · May 14, 2017

NJM15 said:
Sorry,
forgot to say I am shooting a S&W M&P 40
I have the Lee .40 bulge buster and never felt much
resistance pushing one through as I have recently.
I have a storm lake ported barrel I will try next time to eliminate that possibility

I'd try different loads/ammo before I tried a new barrel. In fact, I'd run some factory ammo through it to determine if its the barrel or your hand loads.
If it's the barrel (which I tend to doubt), it goes back to S&W. If it's you hand loads, you need to change one thing at a time to diagnose the issue. I'd start with fresh brass, myself.

SMSgt · May 14, 2017

I must be doing something wrong. I shoot primarily lead reloads in my Glock 30 and have yet to find so much as a sliver of lead afterwards.

ageingstudent · May 14, 2017

bigedp51 said:
If your bulge is around the entire base of the case you might have a large diameter chamber. Or thinner cases with a base diameter at minimum SAAMI diamer

This I think. Likely you are noticing because you are using different brass. My Shield 40 leaves a slight bulge all the way around some brands brass but not Rem or Winchester or Federal. Same thing with my P226. It is very likely the brass. Sort a few out and compare. This isn't bulging like the pics above it's more like swelling.

BZimm · May 14, 2017

Aren't all (most) semi-auto chambers a bit oversized to allow a smooth transition of the new round into battery position? I know the older generation Glocks had the feed ramp cut further in the chamber bottom to minimize feed issues. I know the newer ones have a steeper ramp angle as an improvement to the original engineering. My G23 Gen 4 does not damage the casing any more than other handguns....that I can tell.

I knew of the "Glock Smile" when I bought my G23 over a year ago. I collected my spent brass for a year and couldn't see even a hint of a smile on any of my once-fired stuff. I started reloading back in January and I am fanatical about inspection of any spent brass as it works its' way to my bench. When I bought 1600 rounds of range brass is when I first saw a "smile" on any casing that I handled. I've attached a couple pics of my collection of inadequate brass that I set aside for recycling.

I've handled about 4200 spent casings and these pictures show my entire collection of brass that I won't load. I will continue my fanaticism with reloading preparation and I feel comfortable with that.

To the OP, I'm curious about your statement "Recently I have noticed some bulging about 3/16" above the rim". Is this observation based on science? All the straight walled casings that I have prepared for reloading have had some swelling that required resizing prior to flaring and charging.

Like the gentlemen stated above, the 40SW cartridge headspaces on the case mouth. I think a Lee FCD would help you feel more secure with your crimping step. Read, Read some more, and then Read it again.

PR24 · May 14, 2017

Glock OEM barrels are STILL unsupported. Some of the aftermarket one's are fully supported.

Arub · May 14, 2017

I have been shooting and reloading for a Glock 23 for over 10 years with no bulge related failures. I use the 23 for steel plate, USPSA, and other competitive shoots as well as frequent practice drills. The "bulge" I experience is much less severe than the one pictured above.

As far as leading is concerned, I have had no major issues with commercial hard cast 180 grain bullets. I did experience major leading and tumbling issues using reclaimed wheel weights run thru a Lee 180grain Alox type mold. Problems were experienced with both the Glock factory and a Wolf after market barrel. As long as I stay with the commercial hard cast bullets I have only minimal leading that cleans up easily at the end of a shoot. I clean usually after about 250 to 300 rounds fired.

at_liberty · May 14, 2017

I run all 40 through a Bulge Buster. I never get the pimple of the actual Glock problem but rather a general bulge too close to the case head for the dies to otherwise affect. I concluded that this was caused by the case ejecting while still under pressure, i.e the nature of the beast, not designed to support reloadng. My problem was mostly Kahr rather than Glock. Kahr chambers in my guns are unforgiving, so I just use a cartridge gauge. It's just easier to precondition everything and load to standard dimensions.

427mach1 · May 14, 2017

BZimm said:
Aren't all (most) semi-auto chambers a bit oversized to allow a smooth transition of the new round into battery position?

SAAMI has chamber dimension specifications but that doesn't mean some aren't looser than others. As I mentioned in my previous post, my Ruger has a much tighter chamber than my 4013TSW and it chambers just fine without bulging the cases. My 4013TSW measures out-of-spec and I could not get S&W to answer my question as to whether their chambers are supposed to meet SAAMI specs....

bigedp51 · May 14, 2017

PR24 said:
Glock OEM barrels are STILL unsupported. Some of the aftermarket one's are fully supported.

They say a picture is worth a thousand words........

Glock fixed the problem years ago and the cartridge cases were made thicker.

I have gen 3 Glock 17 and Glock 22 and do not have a bulge problem.

Bottom line, the only Glocks with a bulge problem are owned by people who do not reload and don't know Glock will replace the barrel.

rotor1 · May 14, 2017

FWIW, Lee 2nd edition says to never use reloads of 40 S&W in Glocks or other guns with unsupported barrels. Whether that means the newer Glocks are safer is questionable. Supposedly the "bulge buster" does not solve the problem and perhaps this is the cause of the infamous Glock Kaboom. More knowledgeable persons are perhaps able to respond.

Bulging .40 cases

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