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.
What causes this bulge???
- Thread starter CMV
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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.
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.
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
Member
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.
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.
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
Member
Off-center
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
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
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
Member in memoriam
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
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
OP
OP
CMV
Member
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.
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
Member in memoriam
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
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
OP
OP
CMV
Member
Yes, I'm using the Lee #19 that came with my die set.
rcmodel
Member in memoriam
Well, there you go then!
Try an RCBS #1, or at worst, a Lee #6.
rc
Try an RCBS #1, or at worst, a Lee #6.
rc
OP
OP
CMV
Member
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.
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.
LiveLife
Member
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.
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.
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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
Member
- Joined
- Oct 30, 2011
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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
Member
I didn't know that. Thanks!
OP, your crimp looks excessive in the photos.
bds, that's the purdiest brass I've ever seen!
LiveLife
Member
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
Member
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
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.
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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