9mm bulges when reloading

[daytooday]

I have been reloading off and on for years (more off than on) but am new to 9mm. For some reason i get big bulges when I seat the projectiles. And before anyone responds with smart --- answers yes they are 9mm luger cases and they are the correct diameter bullets, yes the powder charge is correct. (I ask this question on another reloading site and got nothing but smart___ answers). Last year when I tried and failed at the same thing someone told me I might be flaring to much. I have varied the flaring and still the same. One thing I have discovered is when I looked up the deminsions of the cases mine seem to be smaller at the mouth and the base. Yes I did size them with my lee dies. Are case diameters different per manufacturer? Could my dies be messed up? When the dies were new a few years ago I was getting about 75/25 good to bad now 100% bad. And no they will not shoot, I get many jams trying to shoot them. I have never had any problems with anything bigger ie 38,40,45.

[pgdion]

By chance do you have a picture? Only thing I can think of is by 'big' bulges, perhaps the bullet is catching the rim when being inserted and is actually bulging it out (like when you flare a piece of tubing. I was having this happen occasional if I hadn't de-burred my neck enough. The bullet would catch and the case would buckle and bulge out. I still reload my 9mm by hand (Lee loader ... I know, I'm insane) so my setup isn't quite the same but a little more deburing (and just a little more) eliminated the problem for me.

- phil

[rrp]

Maybe too much crimp? All you need to do is take the bell down when crimping. I hope this helps.

[Don H]

My 9mm reloads look the same way, a slight sort of Coke-bottle shape with the base of the bullet clearly defined. Some brass with thicker case walls have the "bullet bulge" a bit more prominently visible. I only crimp enough to remove the flare from the case mouth.

I prefer to have such a "bullet bulge" because it pretty much eliminates any chance of bullet set-back when chambering the round and the bullet nose hits the feed ramp.

If the "bullet bulge" makes you uncomfortable, merely backing off on the sizing die a tad will pretty much eliminate it.

Although I don't recall the manufacturers, I do recall seeing factory-new 9mm ammo with a similar bulge.

[Woody55]

@rrp said:

Maybe too much crimp? All you need to do is take the bell down when crimping. I hope this helps.

I don't reload 9 mm Luger, but I've had a problem with overcrimping in .40 S&W. It resulted in a slight bulge that was still large enough to affect the angle that it exited the magazine from. This caused maybe one in five rounds to jam.

I discovered that I didn't need to bell the mouth of the case to seat bullets. I discovered that I didn't need to crimp either. The problem went away.

[tkglazie]

do you seat and crimp in separate stages or in one step?

[korny351]

As Don said, the Coke-bottle profile is common when loading 9mm. When loading with cast bullets it will be even more pronounced due to the larger bullet diameter. Taper crimp only enough to remove the flair. Going further will bulge the case even more and lessen case-neck tension. Possibly leading to setback and unsafe chamber pressures.

Lee sizer dies are good quality. The carbide ring seems to sit a bit lower than others. This can give some progressive owners fits, as the shellplate adjustment must be very precise for smooth entry into the die. But it also re-sizes the case that much further down. When you compare your dimensions to the SAMMI spec diagrams note that the measurements given on the diagram are maximum values. Minimum values are -0.007 less per the side-note. My Lee die sizes cases to the minimum value which may accentuate the Coke-bottle profile, but allows my reloads to accommodate even tight chambers.

[daytooday]

yes I do seat and crimp in the same stage

[tkglazie]

Some folks (myself included) have better luck seating and crimping in separate stages. It is certainly not required, but if your process allows for it you might want to consider it.

At the seating station you can set the die to just barely remove the bellmouth without actually adding any crimp, and then at the next station you can put a light taper crimp on it (or an FCD crimp, but that's a whole separate discussion that has been repeated over and over).

The added benefit of this is it is much easier to change bullet types when you seat and crimp separately. You just have to back out the seating plug and readjust it to the OAL you need for your new bullet and leave the die body untouched.

It might be worth a shot for a batch or two, even if you are using a single stage and it is a little inconvenient. If nothing else it might help you figure out what is causing the problem when you use your current method

[Sevens]

A picture might solve your problem. If you are loading cast lead bullets and your concern is that the loaded rounds look "wasp waisted" where it appears you can see the entire profile of the bullet through the side of the case -- but yet they shoot and function properly and are safe, reliable and accurate, then the bottom line is that you don't have a problem.

What may not be obvious here is that the 9mm is a tapered round, it's not a straight-wall case, no matter how much we may think or assume that it is. It's thicker at the case head than it is at the case mouth. Yet we resize this tapered case with a carbide steel die. We are effectively sizing the case down even further than it was originally designed.

That's okay -- it works, and it works very, very well. VERY rare that you wear out a piece of 9mm. For sure, you lose them first.

Especially with a cast lead bullet, they do appear to be bulged, but that's just how a tapered case ends up appearing after reloaded.

Another similar example? .30 Carbine. You can make them look awfully similar... and they run great, too.

[korny351]

What may not be obvious here is that the 9mm is a tapered round, it's not a straight-wall case, no matter how much we may think or assume that it is. It's thicker at the case head than it is at the case mouth. Yet we resize this tapered case with a carbide steel die. We are effectively sizing the case down even further than it was originally designed.

Sevens,

I respectfully disagree. The carbide ring in a 9mm sizing die is a tapered sleeve. If you look into the die you will see the ring is much deeper than the ring in a die for a true straight-walled case such as the .38/.357. This is to impart the taper of the original cartridge design. Measurements of a case re-sized in my Lee sizing die.

0.373 at the case mouth
0.384 just above the extractor groove

[daytooday]

Thanks everyone I just tried a few suggestions and I did get a few to work.

Thanks again

[BigJimP]

I think your solution is in that one station where you seat and crimp...like others said, you only need to remove the amount of bell that you put into the case.

I load a lot of 9mm ...but I have separate dies for seating ...and final crimp. My rejection rate...is less than 3 in 1,000 ....and almost all of those are case burrs or occasionally a crack that will open up in a case after the bullet is seated ...and once in a while I get an inverted primer in a case...still not real sure how that happens.....but I tell you this so you know that reloading 9mm isn't a pain in the butt...it can be done very consistently and quickly.

Not that it matters but a lot of buddies and I all reload 9mm ...( and we all shoot 6 - 10 boxes a week of it )...in a variety of Dillon presses SDB, a 550 and a 650 and one guy is using a Hornaday LNL....and none of us are seeing more than 2 - 3 rejections per thousand...and we sweep up all kinds of range brass too.

You may have to go to a more traditional - 3 die set to get it fine tuned.

I would also recommend investing in a case gague....if you get the seating / and final crimp just right ...a finished round will drop in easily and drop out easily. I case gague every finished round...as I box the rounds up and store them ...it only takes a few minutes...and it eliminates any feeding issues by identifying the rejects / pull the bullets...reclaim the components ..toss out the bad case.

[Gerry]

0.373 at the case mouth
0.384 just above the extractor groove

Obviously Stevens was correct in that we are resizing the case smaller than factory spec, otherwise there would be no tension to hold the bullet after seating. And by your case mouth measurement, it seems to be the case (tapered or not). My Dillon die sizes the case mouth to similar dimensions to those you measured.

The SAAMI case mouth spec is .3811 with a .3800 taper crimp. You're resizing your cases almost 1/100th of an inch smaller. It doesn't sound like a lot, but a lot isn't needed for the purpose. Reloading equipment manufacturers at least make an attempt to provide us with equipment that doesn't overwork our brass needlessly. But given that it is sized smaller than SAAMI explains why even a .356" bullet makes visible bulge in the resized case.

[korny351]

Gerry,

SAMMI spec is actually a range, not a number. Figures listed on the diagram are maximum values. Side note reads: Unless otherwise noted body dia. -.007 (0.18). I will agree that the mouth of the case is under-sized to allow for case-neck tension to hold the bullet. But once a bullet is seated, the case walls are pushed out to fall within range. The SAMMI spec is for a loaded round, not a sized case.

[Gerry]

I agree Korney, the case walls are pushed out after seating the bullet, maybe as large as SAAMI spec. That was my point. Hence the visible bulge is usually normal. I do load bullets as large as .358 in 9mm, and they still chamber in every 9mm I tried them in even though the case mouth ends up exceeding SAAMI specifications by a couple thousandths. There seems to be a bit of error margin built into the specs either way even if they are supposedly for maximum cartridge. Anyway, what it proves is that your best case gauge is your pickiest barrel!

[korny351]

Agree. Totally. Just because ammo may be SAMMI spec doesn't mean that your chamber is.

[Sevens]

Hey, good call. I wasn't aware of the different carbide rings. I've learned something here.

Even still, the "look" of a reloaded 9mm round, especially a fat cast lead bullet round, has always (IMO) been because of the tapered case and our inability to completely replicate the look of a factory new round. Coincidence that I see this easily in 9mm and .30 Carbine? I don't think so.

Still, for the OP, does the ammo work? Can you post a picture?

[oldmanFCSA]

Use a taper crimp- do not roll crimp this cartridge.

Sometimes, by backing off a sizing die a lot, crimping bullet may be completed using part of sizing die.

[NC Cruffler]

Bet your sizing die is set to kiss the top of the shell holder, eh?
Back off the die a full turn and it won't squeeze your cases down to the next sub caliber.

[stlbob]

I have been reloading 9mm a while and have started to get this case bulge condition too. I added a few pistols and that may be the reason this started I'm not sure (no Glocks or striker fired pistols). So I had about 1700 rounds loaded check a few and all seemed well then when I went to check them all in a case gauge 30% would not seat fully. I seat and crimp with two dies not a combo. I checked to insure I had the sizing die properly seated then tried to resize the loaded cases with the standard Redding die, no luck. In desperation I tried a 380 auto Lee crimp/sizing combo die and put that in the press with the crimp components removed, this worked on 100% of the cases. I went to the store and bought a Lee crimp/sizer die for 9mm thinking I have found the tool to remove the bulge, this did NOT remove the bulge any better that the Redding die so I went back to the 380. These rounds still have the taper that a 9mm should have but the 380 goes down just a little further than a standard sizing die. The Lee Bulge Buster will NOT work on 9mm due to the taper of the case at the mouth and .010" larger rim. Not saying anyone should do this or play in traffic just saying what I did to fix my the problem.

[skizzums]

good thread, i have many times had bulged cases jam in my chamber, real pain to get out, i also try to resize the brass as far as possible, i will def try backing off the sizing die from now on
i havent ever crimped a 9mm, havent seen a purpose

[DannyB1954]

To OP, the 9mm does have a tapered case by design. that is why it feeds well in machine guns. It is for that reason that they do not make pass through dies to take bulges out like they do 40S&W. Perhaps the cases were deformed a bit shooting in a gun without fully supported chambers, (like a Glock).
Also if you do not flair enough, the bullet pressing into the case can cock and deform the case.

[shoot1forme]

I recently added a S&W Shield to my lineup and after shooting it one day and then going through the cases I had fired I noticed an odd looking 'smiley face' bulge near the base of the case. I discarded all these cases as I figured with as severe a bulge as they had the cases must have been stressed to the max and I would have been leery to re-size and use them again. The Shield seems to have an inherent quirk in the amount of unsupported case in the barrel causing this Glock type bulge. I shoot plated bullets exclusively in the 9mm and when sizing the cases I've had the best luck by not using the 'inside case mouth expander plug. I also don't inside mouth expand my .40 or 45 cases and find this gives a much tighter and more even pull on the bullets with less chance of set back.

[Clark]

In general 9mm has consistently good better case support, chamber walls, and case heads compared to 25acp, 32acp, 30 carbine, 7.62x25mm, 380, 40sw, 10mm, and 45acp. Although there are good examples of the others, 9mm is the one with consistently high safety margins.

I have measured the case support in some 9x19mm pistols.
There are two ways I measure:
1) Take the barrel out of the pistol. Put an empty case into the chamber. Scribe the outline of the feed ramp on the case with a needle. Under magnification, measure the distance from the case head to the line with calipers.
2) Work up an overload until the fired case has a guppy belly case bulge in the shape of the feed ramp, typically ~~~60% more powder than max published in 9mm with 0.190" case support, and under magnification, measure the distance from the case head to the edge of the bulge with calipers.

The difference between these two techniques has to do with the variations in headspace and the variations in case length. The bulge measurements are typically 0.010" longer.
I have done both the needle and the bulge measurement with poorly supported 380s and other cartridges, but shooting well supported [0.190") 9mm pistols where each shot could make the hand hurt for 10 minutes is too much trouble.
So the following are all in needle measurements:
Glock 19: 0.190"
Star M43 0.165"
CZ52 Czech aftermarket barrel 0.145"
Tokarev Chinese 9mm barrel 0.160"
Beretta 92 0.163"
kel-tec P11 0.190"
kel-tec PF9 0.190"
S&W 659 0.183"
Star BM 0.215"
Star Super B 0.193"

The brands of 9mm brass I have cross sectioned and measured have a case web thickness of 0.160", so the difference between that and the case support is the amount of thin unsupported case wall.


pic above same as link below