What causes this bulge???


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CMV
February 11, 2012, 08:32 PM
Loading some 9mm I noticed this today. Mixed HS brass, 115gr Hornady FMJ, 1.122 OAL. On some cases I see/feel the shape of the bullet base on one side of the brass only. Like when the bullet is seating it's going in on an angle & not being set straight?

Is it normal?

Is it something I should correct?

Is it something I need to worry about?

If it's something I can/should correct, how?

I'm thinking maybe I'm not opening up the case mouth enough with the expander die? If I measure before & after OD at the mouth I get .0055 difference so maybe only opening the mouth 5 & a half thou isn't enough to let the bullet get straight on its way in sometimes & it does this? All I can think of.

Anyway, these pics are of the same round. First one you can see the 'bulge' but it's hard to get a good representation in a photo. 2nd pic is same round rolled 180 & no visible bulge.

http://cmv.zftp.com/bulge1.jpg

http://cmv.zftp.com/bulge2.jpg

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Tomcat47
February 11, 2012, 08:43 PM
Is it normal? ....... It happens sometimes

Is it something I should correct? ...... I Do!

Is it something I need to worry about? ...... I would!

If it's something I can/should correct, how? ......... Take your seating die apart and clean it, it could have gunk in it which in turn starts the bullet into case crooked and possibly starts even worse than the end result.

Also make sure your cases are sized right, and trimmed square and no burrs!

You can pull some of those crooked ones apart with Kinetic hammer, and do some investigating. Mark some up with a Sharpie...go through the process (less powder charge or primer installation) and see what is going on.

Yon can always pull them back apart, but marking them up and going through the process... you find the problem.

rcmodel
February 11, 2012, 08:44 PM
Normal.

It is a sign of good case neck tension.
Which is necessary to prevent bullet set-back and high pressure during feeding.

Thicker brands of brass will show it more then thinner brands.

Fuggedaboutit!

PS: It can also be caused by not flaring the case at all to allow the bullet to start straight.
You don't want to flare much for jacketed bullets, but you want enough to get them started in the case straight by hand.

rc

bigedp51
February 11, 2012, 08:46 PM
Its normal especially with carbide dies, the cases were sized smaller than the diameter of the bullet. Seating the bullet enlarged the case "except" the area below the bullet. (wasp waisted)

mizer67
February 11, 2012, 08:47 PM
If it's only on one side of the round, it's called runout. What that means is the round is going in crooked, canted to one side.

The best way I know to cure runout is not to cause it in the first place. You can try more belling. If that doesn't correct your issue, you can try the Redding competition seating die. It is spring loaded and helps straighten the bullet prior to seating.

If it's 360 degrees, then it's fairly normal and that "Coke bottle" shape is cause from neck tension in the brass.

joed
February 11, 2012, 08:48 PM
As others said it's normal. As long as the round chambers without problem you're good to go. When doing cartridges for auto I always take the first one off the press and drop it in a barrel to make sure all is good. I'd hate to do 1000 that don't fit.

rcmodel
February 11, 2012, 08:51 PM
I'd much rather see that then not have enough neck tension to prevent set-back during feeding!!

The wasp-waist look won't blow your gun up.
Telescoping rounds will, or might.

A 9mm is a tapered case, and if you can't see the base of the bullet, it means not much is touching it except the case mouth!

rcl

gamestalker
February 11, 2012, 09:05 PM
9mm isn't a straight walled case, so being that it is a tapered wall the bullet will often buldge on one side, and occasionally all the way around. Belling the mouth more won't eliminate it, or even reduce it for that matter. More bell is only going to cause your mouths to get over worked, resulting in premature splitting.

But the buldge your seeing isn't unusual nor is it a concern to any extent. As long as the round chambers normal your good to go.

I realized many years ago that belling the mouths really isn't necessary unless you are loading non jacketed bullets, which I don't. In fact, I don't ever bell any of my brass, and it hasn't caused me any problems. I chamfer the inside of the mouth just enough for the bullet to seat without shaving. In my opinion, the advantage to seating like this is two fold. First of all, I'm not working the mouth at all, which provides me with 100% unaltered neck tension. The other advantage is I don't ever have to worry about head space being effected by inadvertant over crimping to close the belling.

The 9mm, and a number of other auto loading cartridges head space at the mouth, so if someone were to over crimp it would interfere with head space, which could cause potential FTF's, ruptured cases, bullets can get pinched during firing which can raise pressures on an already pressure sensitive cartridge, and it distorts the bullet. And in the event a case gets over belled or the crimp isn't closed sufficiently, it can cause neck tension issues or cycling issues.

Walkalong
February 11, 2012, 09:10 PM
Looking good.

Striker Fired
February 11, 2012, 09:50 PM
Technically it's not right, something isn't perfectly straight with each other or holding/feeding square & stright. Ideally the shell holder should be square, straight and hold the case tight, the bullet seater die should be square and perfect in alignment with the case as it enters it. Thats the perfect world, where everything is exactly the same size,length,ect...

The real world has a little slop because things are not perfect,so in order to work with all differences,things need to move.This is the result.You can take extra time and make sure everything is clean and perfectly square and in as close to perfect alignment as possible(probably a good idea anyway) and it will help,but is it worth it? For the most part , no. As long as they come out REASONABLY aligned you'll be good.

It is hard to get every round to come out even ,especially on progressives. I have taken the time and got true rounds using my single stage, but not on any progressive. That time I was testing some 45ACP rounds and with 10 straight and even,the other 10 "offset"more to one side,I could not tell in accuracy between the two. That was my only comparison,but I'm sure others have tested it also.

jcwit
February 11, 2012, 09:52 PM
Once again rcmodel hit it on the head!

243winxb
February 11, 2012, 10:28 PM
Like when the bullet is seating it's going in on an angle & not being set straight?
Make sure your bullet seating stem fits the bullet nose correctly. Use a die that bells & expands the case mouth. Seeing the base of the bullet is ok if 360 degrees. Not on 1 side. IMO.

Bovice
February 11, 2012, 10:43 PM
Not sure what dies you are using-I use Hornady. My seating dies have an alignment sleeve in them to help keep the bullets straight. You might want to consider them if you're worried.

CMV
February 11, 2012, 11:13 PM
I'm using Lee carbide dies. FL resize, powder-through expander, and the seating die. FCD installed on 4th spot on ring but I'm not using it.

cfullgraf
February 11, 2012, 11:19 PM
The bulge is a common occurrence in reloaded 9x19. If you have some concerns remove the barrel from your pistol and see if they chamber before ruining them with the FCD die.

The barrel of your pistol is the best case gauge ever for your reloads.

As an aside, the case walls of a 9x19 are straight, they just are not parallel.

jcwit
February 11, 2012, 11:22 PM
Looks like a plated lead bullet, right? If so what does it mic. at? I'll bet its just a thousandth oversize which would be correct for a lead bullet, plated or not.

Tomcat47
February 11, 2012, 11:25 PM
+10 on Hornady! I love there die sets. Have a lot of Lee, but I got Hornady for my most popular calibers.

CMV
February 11, 2012, 11:32 PM
115gr FMJ Hornady. They mic @ 0.3555.

jcwit
February 11, 2012, 11:36 PM
Well that blew that theory.

sugarmaker
February 11, 2012, 11:47 PM
Not serious. Misaligned bullet on case when seatiing, or lots of room in the seater die (lee dies), not enough bell to get the bullet on the case straight, having the wrong shaped seat plug on your die.

The round will shoot fine, no effect on the target as the ammo is still better than the gun.

Naterater
February 12, 2012, 12:51 AM
I get this all the time. NORMAL.

Tomcat47
February 12, 2012, 01:05 AM
I too see it as a "Normal" issue reloading 9mm,

However as the OP stated, he sees it one sided sometimes
(Bulge on one side) Not what one likes to see......I will take them back apart myself.

This can usually be remedied by cleaning the dies and making sure the cases are sized right and they are square and free of burrs.

Walkalong
February 12, 2012, 10:19 AM
The bulge is a common occurrence in reloaded 9x19. If you have some concerns remove the barrel from your pistol and see if they chamber before ruining them with the FCD die.

The barrel of your pistol is the best case gauge ever for your reloads.

As an aside, the case walls of a 9x19 are straight, they just are not parallel.

Only get worried if one side has none and the other has a lot. Other than that, no worries.

bds
February 12, 2012, 12:21 PM
Not serious. Misaligned bullet on case when seatiing
However as the OP stated, he sees it one sided sometimes
(Bulge on one side)
Only get worried if one side has none and the other has a lot. Other than that, no worries.
I get very slight bulging when seating Winchester .355" jacketed FMJ but (due to sharp flat base of the jacketed bullet) if the bullet gets tilted during seating, case will show more pronounced bulging on one side (see bottom picture). Like many posted, even the cases with bulging on one side shoots fine.

Typical case bulging with 115 gr FMJ (same amount of bulging all around the case)
http://www.thehighroad.org/attachment.php?attachmentid=158881&stc=1&d=1329063625

More pronounced bulging showing on one side of case due to bullet tilt during seating
http://www.thehighroad.org/attachment.php?attachmentid=158882&stc=1&d=1329063625

rcmodel
February 12, 2012, 12:50 PM
Crooked seating?
Not always.

More bulging on one side then the other can also be caused by non-symmetrical brass.

If one side of the case mouth is thinner then the other side, you will get more bulge on the thin side, because it is easier for the bullet base to expand it then the thick side.

rc

rg1
February 12, 2012, 12:58 PM
I like to see the bulge just below the bullet base. It says you have good neck tension and it will prevent the bullet from being pushed deeper into the case when chambering. It indicates the bullet was not seated exactly straight if there is more bulge on one side of the case than the other side. I didn't have much luck with my standard seating dies in 9MM, 45ACP, 40 SW until I tried Hornady's seating die with a sliding alignment sleeve. It practically eliminated bullets slightly seated crooked. In pistols you probably won't be able to tell the difference in accuracy with a slightly off centered bullet. Like mentioned, 9MM and other tapered cases will be sized straight down with the carbide sizer ring and this will reduce the case walls and will create this bulge under the bullet base.

918v
February 12, 2012, 01:19 PM
The reason the bulge is more pronounced on some and not on others is because each case is unique. Contrary to popular belief, case wall thickness is not uniform throughout it's cirfumfrence. The case will bulge where the case wall is thinnest. Some cases will be more uniform than others.

Another cause of this bulge is crooked bullet seating. Again, contrary to popular belief, the seater stem will not straighten out a bullet started crooked in the case mouth. Taking extra care during this step will make your rounds look pretty.

Walkalong
February 12, 2012, 02:17 PM
+1

Start em straight to get em straight.

But rcmodel and 918v are right, cases with a thin side will do this to some degree no matter what.

rogn
February 12, 2012, 02:33 PM
The more seating tension you ave the more likely you are to have a visible bulge. If the case expander gives only a few thousandths tension , the seated round will show less bulging that one with several thousandths has. I suspect the gentleman with the Hornady dies has a larger expander than some of the others. I can't prove that as I don't have a Hornady 9mm set, but I suspect it.

beatledog7
February 12, 2012, 02:53 PM
I've had a few 9mm bullets of various types and weights seat with a little bit of runout, but all of them have gone bang and hit within a couple inches of where I aimed them at 15yds or so.

If I were competing or working up rounds to shoot into, say, MOA at 25yds, I'd spend more on the bullets, sort the brass by headstamp, flare a bit more, seat each one as straight as possible by hand, then press them home.

But I doubt it would make much difference in the end.

joneb
February 12, 2012, 04:06 PM
If it's something I can/should correct, how?

I was having that same problem, and it bugged me.

What I noticed is that neither the flare/expander stem or the seating stem were centered in the die body they were off axis. The reason for this is the amount of tolerance in the male and female threads the threads are at a pitch and when the nut is tightened the shaft will move from center.

I was having a really hard time with 9x18 Makarov and seating 95gr LRN no amount of flare or attempt to start the bullet straight was helping, the bullets were noticeably out of line.
So just for fun I took out the tolerance, a single wrap of masking tape around the smooth part of the stem and a even number of wraps of teflon tape on the threads of the stem fixed the problem. Now the bullets are seated in line with the case, the bulge of the bullet is consistent 360 degrees around the case.

Lost Sheep
February 12, 2012, 07:49 PM
As soon as I read that the bulge was only on one side, I thought of something similar to jibjab, but read through the thread to make sure no one else suggested it already.

First question: Is the bulge always the same orientation when you cartridge comes out of the press? This points to the die (as jibjab suggests) as the source, or the press itself (either the shell holder, the ram or the press' frame).

Try this. Ensure the shell holder is all the way installed on the ram and centered. Then make sure the cartridge case is all the way into the shell holder. After you insert it, give it an extra, gentle push with just your fingertip, very near the base. See if that cures the asymmetric bulge.

If that doesn't cure it, try turning the shell holder 90 degrees and seat a few more. If the orientation/direction of the bulge changes, the shell holder is suspect.

Another experiment is to back the die body out a couple of turns and the seating stem in by the same amount. Seat a few rounds (without crimp, obviously, since you backed the body out). Is the bulge still there and one-sided just as before?

After you get the bullets seated, you can back the seating stem (all the way) out and apply the (taper) crimp alone.

If you REALLY suspect the brass thickness being the reason the bulge is asymmetrical, try this: Mark a couple of cases to show where the bulge is. (Mark on the case head; a mark on the side of the case may come off during sizing.) Size those cases, do not prime or powder them, but bell the case mouth. By hand, insert and seat a bullet (you will probably have to use a light hammer to tap it in unless you have a vice or c-clamp). The idea is to separate die alignment from the experiment. If you find a bulge in the same position as it was before, I would strongly suspect the brass thinness is the reason for the asymmetric bulge.

Ain't science fun?

Lost Sheep

Walkalong
February 12, 2012, 08:04 PM
What I noticed is that neither the flare/expander stem or the seating stem were centered in the die body they were off axis. The reason for this is the amount of tolerance in the male and female threads the threads are at a pitch and when the nut is tightened the shaft will move from center.Try running a case up into the expander with the nut loose, then tighten it down with the case holding it centered.

joneb
February 12, 2012, 09:25 PM
Try running a case up into the expander with the nut loose, then tighten it down with the case holding it centered.
This may help center the expander/flare plug but doesn't address a off axis seating stem. I think both dies need to be set up properly for minimal runout, this is assuming the dies are in-line with the press and the press is in-line to its self.

rcmodel
February 12, 2012, 09:28 PM
You can do that too.

Just leave the lock-nuts loose, then run a "perfect" loaded round up in the die, jiggle them around to center the threads, and tighten the lock-nuts.

It is SOP here when setting up rifle dies, and will work as well with pistol dies.

rc

CMV
February 12, 2012, 09:31 PM
Interesting ideas guys. I don't get it with every round so it it was a problem with the die or the press having an axial alignment issue wouldn't it happen to every one?

I'll experiment some more later in the week when I run some more 9mm and pay attention to the orientation as they come out to see if I notice a pattern when it happens.

rcmodel
February 12, 2012, 09:45 PM
O.K., one more idea.
Are you by chance using a Lee shell holder?

They make two different ones for 9mm.

The Lee #19 is a "universal" size they ship with die sets that can be used for .30 Luger & Mauser, 9mm, .357 SIG, .38 ACP, .38 Super, .40 S&W, 10mm, 9x21, and a few others.

Of course, it doesn't fit any of the smaller ones correctly and center the case under the die like it should.

The Lee #6 is made specifically to fit 9mm, and does center the case pretty well.

rc

CMV
February 12, 2012, 09:46 PM
Yes, I'm using the Lee #19 that came with my die set.

rcmodel
February 12, 2012, 09:47 PM
Well, there you go then!

Try an RCBS #1, or at worst, a Lee #6.



rc

CMV
February 12, 2012, 09:51 PM
Grrrrrrr....another frickin Lee shellholder. LOL!

I really do like their stuff. the only complaints about anything Lee I have is (1) that rinky-dink POS scale and (2) the ginormous amount of shellholders you need - one for the press, one for the hand primer, one for the trimmer....now a different one than what they provide with the dies to actually fit - ha!

I'll stop by the fun store on Tues if I get a chance to leave during lunch & pick up an RCBS #1 & give that a try.

bds
February 12, 2012, 10:38 PM
Wait, before we jump to any conclusions ... ;) I don't think it's a #19 shell holder/plate issue (I've been loading a lot of 9mm FMJ/plated/lead loads for quite a few years and have not seen this one-sided bulging attributed to #19 shell holder/plate alone). On very RARE occasions have I seen uneven bulging due to uneven case wall thickness ...

I am also using #19 shell plates (I have three) along with #19 shell holders (I have two - I do load development in the single stage press) and DO NOT get the "one sided" bulging problem normally when loading 9mm FMJ with mixed head stamp range brass (see top picture - the slight bulging shown is same all around the bullet). I ONLY get the "one sided" bulging when a bullet gets tilted during seating (see bottom picture - these were intentionally tilted for the picture and the bulging is only on one side, the other side is flat).

I would have the OP check the inside of the bullet seating/taper crimp die to make sure the seater/inside of the taper crimp die is clean and apply enough flare so the bullet base is set flat inside the case flare when seating the bullet.

Also, in contrast to the sharp/flat base of the Winchester .355" 115 gr FMJ bullets, when using rounded bottom 115/124/125 gr plated bullets, I have even less of a problem with bulging EVEN WHEN bullets are tilted - the rounded bottom helps align the bullet in the case neck as the bullet gets seated. With larger diameter Berry's plated bullets (.3555"+), the bulging is greater, but equal all around the bullet.

http://www.thehighroad.org/attachment.php?attachmentid=158881&stc=1&d=1329063625

http://www.thehighroad.org/attachment.php?attachmentid=158882&stc=1&d=1329063625

joneb
February 13, 2012, 11:13 PM
Try running a case up into the expander with the nut loose, then tighten it down with the case holding it centered.
This may help center the expander/flare plug but doesn't address a off axis seating stem.
I make a lot of adjustments on my seat/crimp die. By taking out the slop and having the seating stem centered in the die body is a real plus for me.

Walkalong
February 14, 2012, 08:40 AM
I make a lot of adjustments on my seat/crimp die.Seating depth, or crimp change?

I like to use a Hornady or Redding seater with a micrometer top. the Hornady is hard to read, but much cheaper. Both seem to do a very good job seating, and you can dial back and forth to a setting. You can still center them as was described. Then I use spacers under my crimp dies. I get the die set for a firm or heavy crimp (centered the best I can), then use spacers to get the different crimps I want. A few seconds each time to get it "centered" and I am good to go, but it doesn't seem to matter much on the crimp die. The round seems to want to center its self.

Sometimes I just screw the dang things in and load. I can't really prove a difference on target anyway. Not with pistols.

Striker Fired
February 14, 2012, 11:20 AM
I'm shooting pistol league right now and had a batch of my pet load for my XDM40 loaded up carefully.They were done single stage and were pretty good as far as centered,the bulge was even.Well I ran out and just quickly set up my LNL, which I haven't played with as far as getting good consistant and straight loads.Quite a few of them had more of a bulge on one side than the other,not extremely bad,just easy to see, well I shot last night and my score was right where it always had been,no fliers and the hit in the same place as my "better" crafted ones. I have a couple weeks of ammo left,so I'll know for sure if it pays to worry about it.

MtnCreek
February 14, 2012, 12:27 PM
Are you by chance using a Lee shell holder?

They make two different ones for 9mm.
I didn't know that. Thanks!

OP, your crimp looks excessive in the photos.

bds, that's the purdiest brass I've ever seen!

bds
February 14, 2012, 01:13 PM
MntCreek, thanks! Top picture cases with slight bulge all around were done with fine grit walnut media and NuFinish polish. Bottom picture cases with more pronounced bulge on one side were hand polished to eccentuate the bulge and the shine is enhanced by lighting.

AABEN
March 14, 2012, 08:37 PM
You need to set your die to expand the case more. All I would clean the setting die good and are adjest it. GOOD LUCK

malpais
March 15, 2012, 02:11 PM
Hi all, my first post on this forum.

I am a beginner at reloading and have experienced the same issue using once-fired Geco cases.
My first idea was that Lee sizing & depriming die is too tight, but after all I did install it according to instructions (down to the baseplate, then backed off 1/8 turn just to avoid it "slamming" into the plate and tightened the nut).
BTW I have a Lee Loadmaster press, the dies came in a set with the press.

But even though if the sizing is correct, and the case ends up "perfect" size and assuming the seating is correct, then something does not make sense; I have looked without measuring at Geco, S&B and Finocci ammo and they all seems to have much less taper out-of-the-box than Lee-sized cases. Almost straight-walled I would say. Do they make a "less tapered" 9mm case, or do they use smaller diameter bullets?

Now personally I could care less if this is just a cosmetic issue, and that cases will end up stretched back and forth becase I won't reload them again, but what I want some things:
1) Has anyone had FTF/FTE problems with cases that bulge like that? (assuming this is not a seating/bullet tilt issue)
2) The bullets that are seated in such "overtight" cases - they don't need crimp, do they? I have a hard time getting them out with a puller... crimp seems unnecessary here.
3) Pressure/case capacity issues because of the very strong "crimp" as the bullet gets seated that firm?

BTW, loading them with N330.

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