9mm case bulge

[okdoesthiswork]

I have a problem that baffles me. I checked the brass in question with a case gage before loading and they are fine. Bought prepared and also some I have done that were rolled so good even taper on the brass. Bullets measure .355 and I have used 124gr FMJ, Winchester 147gr JHP and Federal 147 HST JHP. The bulge is not case maker specific. I have reduced the bulge rate by going slow and twirling the bullet in the top of the case as it is going into the seating die. I have adjusted everything I can think of and tried different shell plates too.

 

  Now above and beyond this other things are going on too. For instance the adjustment on the side of the powder dispenser where that plated bracket ties into that formed rod has a lobe that supposed to touch the casting when the handle is pulled all the way down. Well I cant adjust this to just touch and instead it hits pretty hard. The powder bar seems to have play in it going in and out and does not seem to meter to a hard stop. I am going to try Dillon this week to see what they have to say but what I would really like is to find a mentor in southern middle Tennessee who is familiar with the dillon rl750 and might be willing to stop in or have me drive over there to meet.

[MikeyScuba]

I had something similar but I was playing with a Lyman M die.  They shot perfectly fine though but yea its aggravating.

 How is your flare on the powder measure?  Pic?

[okdoesthiswork]

I have varied the flare up to the point of too much just to see. I have gone fast and slow and in between and slowed down the stroke at each end of handle movement and all I do is reduce the failure rate. Many of these will not fit the case gage and if they done my Glock wont shoot them. One of the things that puzzles me is many times it seems to be 180 degrees around the case is bulged much more than the rest. I am getting up to a 10% failure to gage at times and I cant keep wasting stuff trying to find the answer.

[zombywoof]

Headstamp?

[dansedgli]

Some brass is thicker than others as you go down towards the base. This bulges out with heavier projectiles as they go in deeper and push out more material. 

 

I tried to get 145's to work but at the cost of sorting by headstamp it wasn't worth my time. 

 

Back to 125's and no bulging.

 

 

[AHI]

This has been discussed many times. A little search will reveille hours of information.

1 - are you seating the bullet straight.

     use a mr bullet feeder expander

     either a Hornady or Reading bullet seater (bench rest style)

2- over all length

     The longer you can load the better. 9mm brass has a internal taper 

     the shorter OAL the more issues you will have.

3- As stated above some cases are thicker. (see #2)

[Jim Watson]

It might be time for the infamous Lee CFC.  I use one and just motor on.

 

I tried an MR expander and got nowhere, the "M" step is barely perceptible on the expander and makes no difference on the brass. 

Edited April 26, 2021 by Jim Watson

[pyrrhic3gun]

I agree with AHI's #1.  I began reloading 9s after a long layoff due to COVID restrictions.

Had the wrong bullet seater in my press.  Caused these off-center bulges at the base of the bullet and some bullets were even obviously crooked in the case.

Put in the round nose seater and it fixed the problem.  So, you want to make sure you have the right seater to guide those huge hollow-points into the case straight.

[okdoesthiswork]

Thanks for the help all. A miniscule shorter seating depth made for a lot of improvement. Going to try the round nose seating die idea tomorrow. It does not seem to be case specific insofar as which one bulged the worst.

[noylj]

If they chamber, it is fine. Is it a "wasp waist," where the "bulge" goes all around the case? This is generally considered very good. It will help prevent the bullet being pushed into the case. The sizing die must size the case OD down to x.xxx inch diameter no matter the case wall thickness. When the expander brings the case ID up to just below bullet diameter, it only expands as far as the designer believed the bullet would be seated, so the case below that point is NOT expanded.

If there is an actual bulge on just one side of the case, the bullet is seating crooked. Best solutions are more case flare and a seating stem that actually fits and controls the bullet. For custom seating stems, I request no contact with the bullet nose with contact as low down the ogive as possible

[HesedTech]

This issue has been covered multiple times, do a search of the forum.

 

However it is always the same things:

• Case internal thickness.
• deep seated heavy bullets.
• Short OAL, seated deep, because of bullet 
• misaligned bullet during seating.
• ‘CBC brass the worst offender 

For the price, in my opinion the Hornady seating die is the best for 9mm, but most work fine.

 

 

[NETim]

I put a wad of hot glue on the Dillon RN seating die stem.   Then I pressed a bullet into the glue while it was still warm (coated 124 gr RN).   I think it gets me a more consistent finished round, OAL wise.   No doubt it helps with concentricity as well.  

 

I also believe the Mr. Bulletfeeder has helped with a more consistent finished round as well.  (Bullets seated straighter more consistently.)

 

 

[okdoesthiswork]

On 5/1/2021 at 4:51 AM, noylj said:

If they chamber, it is fine. Is it a "wasp waist," where the "bulge" goes all around the case? This is generally considered very good. It will help prevent the bullet being pushed into the case. The sizing die must size the case OD down to x.xxx inch diameter no matter the case wall thickness. When the expander brings the case ID up to just below bullet diameter, it only expands as far as the designer believed the bullet would be seated, so the case below that point is NOT expanded.

If there is an actual bulge on just one side of the case, the bullet is seating crooked. Best solutions are more case flare and a seating stem that actually fits and controls the bullet. For custom seating stems, I request no contact with the bullet nose with contact as low down the ogive as possible

No this is not just wasp waist. Part was Dillons video recommended the sizing die be set down right next to the shell plate. Doing so made them to small and so I learned to back off.

 

  Often the case just above the base being too big to gage. So then I get some rolled and then I size them and this was better but still way to many rounds that would not gage right. There has been an enlarged portion at the case next to the base and then a ring pushed out around the base of the bullet either or both preventing gaging. Not oversizing and setting bullet depth a little shallower and flipping the seater to round nose has eliminated most problems now. Going through the learning curve I guess as there is no one I can find locally to spend part of a day with me to mentor.

[rooster]

Try this. Size case, check in gauge. If it gauges then there are only 2 things that will prevent the gauging of the loaded round, oal or crimp. Some gauges have a step that your bullet will touch, others are pass through like the shockbottle. If you know your crimp is good then there is something wrong with your bullet. 9mm crimp is usually.376 to .378. I think sammi spec is .380, but that’s cutting close in your match chambers.

[noylj]

Wish I could see set-up and problem.

Again, do they chamber in your gun? F the gage. If they chamber in gun, they are good to go. I have never had a gage, never wanted a gage, and never needed a gage.

Raise shellplate all the way up. Screw in Lee or Hornady sizing die (Dillon dies size down the least) to just touch sheelplate. Lower ram, insert case in shellplate, raise ram and size case. At the same time, turn lock ring/nut down to lock die body in place with case still in die.

You may want to get a Lee 9mm MAK fcd, remove the crimp guts, lube cases, and bulge bust all your cases to eliminate any bulges.

[rooster]

As long as you know that the gauge is tighter than your barrel it does come in handy because you don’t have to take your gun apart to check rounds. What I do is flair the case insert a bullet backwards and crimp so that it just removes the flair. Check it in your barrel, it shouldn’t fit, then try it in your gauge it also shouldn’t fit. Keep reducing crimp just a little and keep trying in your barrel and your gauge. When it finally plunks in your barrel and hopefully not your gauge you know your gauge is tighter than your barrel. Keep crimping until it fits your gauge, now you only have to find the oal that fits your barrel. That’s why I turn the bullet backwards you don’t want the ogive of your round influenceing your measurement. 

[noylj]

But, of course, you take your gun apart every time to clean it?

People do what they want, whether any one else understands why.

To me, it takes so little time to pull a slide and remove the barrel...

Still, in the last 20 years, I have had one round not chamber. It seized up my P-08 "Luger." Got gun apart and it was a raised ridge, looked like from a feed ramp bulge (like the sizing die had simply changed a very slight bulge and moved it down the case to form a raised ridge), that I didn't even see when inspecting my cases. Still, took a lot less time to solve the problem than 20 years of gaging every round...

Maybe gage for important matches, but I think I solved the problem by bulge busting all my 9x19 and .40 cases. That was about 5 years ago and no issues since then.