Do 9mm cases get bulged from unsupported chambers?

[rajbcpa]

...so this is a well known problem with 40sw brass that get bulged when used in an unsupported chamber.

Does this happen with 9mm too?

If yes, are there any dies to fix this? These cases are tappered and not stright; right?

[Unclenick]

The barrels don't usually leave quite as much unsupported on the smaller diameter case, but it can happen, especially with +P loads. The 9 mm taper continues to the rim, so the rim is about 0.004" wider than the body at the datum 0.200" forward of the back end of the case head, technically making it a "semi-rimmed" case, but only very slightly so. The rim dimension has a -0.010" tolerance, while the 0.200" datum has a -0.007" tolerance, making the minimum rim only 0.001" larger than the minimum datum diameter. (See here.)

So, you can take the 9 mm Lee Factory Crimp Die, unscrew the crimp ring retainer cap and remove the crimp ring, then just use their bulge buster kit to push the 9 mm cases through. It'll take maximum dimension rims down slightly, but they will still work just fine. Worst case you'd have to deuburr the rim with a quick swipe over a flat file.

[BDS-THR]

I do not believe you can "push-through" resize 9mm cases using FCD as the base is larger than the case mouth/neck - http://leeprecision.com/case-conditi...ge-buster-kit/

NOTE: 9mm cases are not able to be used in the Bulge Buster because it has a slightly tapered case and the rim is not completely flush with the case.

9mm Glock barrels have comparable case base chamber support as Lone Wolf/KKM barrels and don't seem to bulge the case base as much as 40S&W cases fired in factory Glock barrels with hot loads (And I load 9mm jacketed loads to near max load data).

Here's a bulged 40S&W case showing the "guppy belly"



Here's a bulged 9mm case showing a smaller "guppy belly" (keep in mind that 9mm is a tapered case and the bulge shown is actually less than what it appears)

[rajbcpa]

Interesting... the bulged 40 cases I was dealing with this past weekend were bulged at the base - near the extractor ring.

[FlySubCompact]

BDS-THR,

Do you reload those .40 cases? Just curious, because I'm kind of scared to reload my bucket full of .40 guppies.

If you do, what fps and bullet do you use?

[Steviewonder1]

Never had an issue with any bulged 9MM case. I just did a test run of 25 9MM cases I fired that were Winchester Ranger T's 127 GR +P+ and all chamber checked in my Dillon Guage. Looks like my G-19's hold up well under the +P+ with no bulge. YMMV.

[jepp2]

Here's a bulged 40S&W case showing the "guppy belly"

I don't consider your case to show the "guppy belly". They just show the normal case expansion for being fired in a barrel with a generous chamber. The bulge is way too far up the case from the head to be due to the unsupported chamber that can cause the guppy belly. My guess is they have the glock impression on the fired primers. Glocks are know for having generous chamber.

[Gster]

[Quote] Do you reload those .40 cases? Just curious, because I'm kind of scared to reload my bucket full of .40 guppies.
You can get a bulge buster kit or just send me the .40 brass and I'll put it to good use, I'd pay the shipping of course.

[BDS-THR]

Originally Posted by FlySubCompact

Do you reload those .40 cases? Just curious, because I'm kind of scared to reload my bucket full of .40 guppies.

If you do, what fps and bullet do you use?

As others have posted, yes. These will get sized back flat with Lee carbide resizing dies and they will come out like the picture below. My QC whether to reload a bulged case or not is when a overly bulged case does not fully resize with Lee carbide resizer, I will rotate the case 90 degrees and attempt to resize again. If it won't resize on the second attempt, I deem the case too far stretched/thinned and toss the case in the recycle bin. Yes, you could "fix" the overly bulged bottom of the case by push-through resizing with FCD/G-Rx die but you just can't add metal back to the case wall to make it thicker by any amount of "fixing"

I reserve verified "once-fired" 40S&W cases that were not overly bulged (passed the resizing test) for max load data. For mixed range brass with unknow reload history I will use mid-to-high range load data. (even bulged cases loaded several times with "hot" loads and fixed with Lee FCD/Redding G-Rx "Glock Rx" dies that were dry tumbled/wet tumbled with S/S pins will look like any other spent case). For 40S&W, I prefer not to use faster burning powder than W231/HP-38. Mid-to-high range loads using W231/HP-38/Unique/Universal would be my suggestion for lower pressure 40S&W target loads. I use Montana Gold/Speer Gold Dot/Remington Golden Saber JHP and Berry's/PowerBond/Rainier/X-Treme plated and Missouri Bullet Company 18 BHN lead bullet for 40S&W loads.

Originally Posted by Ejepp2

They just show the normal case expansion for being fired in a barrel with a generous chamber. The bulge is way too far up the case from the head to be due to the unsupported chamber that can cause the guppy belly. My guess is they have the glock impression on the fired primers.

Yes, these spent cases showing the same bulge were shot from Glock with factory Glock barrel as indicated by rectangle primer indents. The amount of bulge showing on these cases would be the extent I would feel comfortable reusing the case. If I see bulging greater than these and they fail to resize on second attempt rotated 90 degrees, I toss them in the recycle bin instead of fixing them with FCD die. But that's me, YMMV

Be safe

[noylj]

Yes. They also get bulged due to being loaded to 9mm Major levels.
If you can see the bulge, the case is damaged and should be crushed and thrown away.
I use a Lee 9mm Mak FCD die body and their bulge buster to "iron out" my 9x19 and 9x21 cases.

[FlySubCompact]

Thanks BDS. My worst "guppied" cases don't look any worse than the ones you've shown.

OP, sorry for the slight highjack. Now back to 9mm...

I do reload 9mm, but I'm using a Lone Wolf 40 to 9 conversion barrel in .40 cal Glock. The LW barrel is tighter, so I do get very slight bulges. The Loadmaster progressive press and Lee carbide dies put mojo on them. I've reloaded a bunch of cases that have made three or four trips through my gun.

[jmorris]

They are not as big of a problem (40 isn't either) as many make them out to be but cases can get bulged. The ones that have the most problems are the ones we shoot through SMGs even 45 acp's have problem then.

I automated a casepro to roll size cases back to spec. It even cleans up and nicks in the extractor grove. No push through sizer can do that.

[TrentSr]

^^ You win Reloader of the Year man.

Heck of a contraption.

[spacecoast]

A fair number of my 9mm cases are adjusted by the Lee FCD down about where the "guppies" are shown in the picture. I've never had a problem reloading or re-shooting them.

[Unclenick]

Shouldn't be an issue. Lube them, if necessary, to push the rim through, but it should size down. If you've ever run a .45 cases into .44 dies before by mistake, you'll know even thicker brass near the head can move a few thousandths with no problem. All you're worried about is not getting the rim so small the extractor can't drag it out of the chamber, and the FCD ring shouldn't make it that small.

Of course, if you're trying for bull's eye match loads, that smaller diameter reduces coaxiality of bullet alignment with the bore. For steel plates it should be meaningless, but for a 50 yard X-ring, you don't want to bet on it. But then, bull's eye target shooting loads are normally too mild to cause bulging in the first place, unless your chamber mouth's been significantly recut during accuracy work.