Bullet Seating Question

bkhann · February 8, 2010, 07:41 PM

I loaded 100 9mm rounds today using Montana Gold 125 gr FMJ bullets, VV N-340 (4.5 gr) with a COL of 1.142".

During a inspection of the finished loads I see that most of the bullets are slightly off center. If you roll the load on a flat tabletop this is quite obvious. I compared some moly/poly 9mm loads that I did some time ago, and those bullets seem to be better centered inthe cases.

Has anyone experienced this and it it something to be concerned about? Is there possibly a problem with my equipment (useng Lee Turret Press with Lee dies)?

88KEYS · February 8, 2010, 10:22 PM

I have loaded thousands of 9MM & 45 ACP; I did not check my load book on the OAL sounds ok, for that round. I think what you have done is set the bullet off center in the case; the problem could have been caused by several factors. I will just give you what I think based on my own learning by making mistakes, and now have been at it about 30 years.

If you belled the case mouth off center more like an oval then round, and then started the bullet in the case for seating, it could have seated it off center. The other thing is the bullet could have been started off center with a slight lean to one side when placed in the case. The seating die should have centered it, but have seen rounds act in strange ways when loading.
I would not shoot them as they are off center the bearing surface of the bullet will be greater on one side of the barrel. I would make sure all dies are set up properly and cleaned; seating dies can build up wax from lead bullets.
Also your seating die does it have more than one stem, like Flat and Round Nose?

The crimp what type applied, a die like the Redding Profile Crimp Die, will center a bullet and apply even crimp around the entire case. I think looking over the case and dies you should find the problem, it is a testing process.
Good Luck

wilkersk · February 9, 2010, 02:13 AM

Yeah,

1) check your seating plug. RCBS seating dies come with 2 different plugs, 1 for flat points and HPs, the other for round nose.

2) Only flare (expand) your case mouths just enough so that the bullet will sit in the case mouth while you raise the ram up into the seating die.

3) always proof the 1st couple of your reloads in every batch by checking with a case gauge, or the barrel from your field stripped pistol that you're reloading for.

Wobbly bullets suck for accuracy. If they don't strike the lanz of the barrel true, they won't be true when they leave the muzzle.

colospgsAVID · February 9, 2010, 02:59 AM

I would be concerned. I don't have a whole lot of experience, but, I know concentric rounds equal accuracy. I've never had this problem before. I've loaded a lot of 9mm and damn they are concentric! I'm using lee dies in a rock chucker. Flare the case as minimally as possible, when you seat the bullet, after charging, hold it as parallel as possible. It should be a smooth feel as you seat the bullet. I am surprised it didn't feel off. Unless your bullets are at fault, I'd say it's technique.

bkhann · February 9, 2010, 07:23 AM

I took a look at bullet lengths this morning.

The 124 gr 9mm FMJ bullets that are not seating straight are 0.581" long.

124 gr 9mm JHP bullets that I have are 0.575" long (I currently do not have any loaded.

124 gr hard cast lead bullets that I use are 0.575" long (these I have recently used and appear to be seated perfectly straight).

With a VV N-340 powder charge 0f 4.5 gr, it appears that the longer FMJ bullets might be compressing the powder.

I wonder if this might be contributing to the problem.

I think that I will load a couple 9mm FMJ loads with no powder to see if the problen is a case fill issue.................

Just re loaded test loads. The 0.581" bullet has some concentricity issues, the 0.575" bullets do not; so it appears that the problem is with using the slightly longer bullets. All 3 bullets are the same diameter.

Go figure !!!!!

88KEYS · February 9, 2010, 03:07 PM

I will agree with the person that posted that you should chamber the rounds "in the gun" that will use them. This is a step I still do every time I load rounds, will fill a mag and cycle them through the weapon. Then closly inspect them for marks and indications the OAL is long and the bullet touched the rifiling.

Using empty case's and loading is a good way to see what is going on, it is testing and finding what works. I have a cheap eye glass from the drug store works fine for inspection, make sure you have good light.

hazfam2 · February 13, 2010, 08:17 PM

I think you might have your crimp die set a little to deep. I had the same problem until I did away with the crimp.l

bkhann · February 13, 2010, 10:47 PM

No, it turned out to be a problem with the seating die. It turns out that the nose of the bullet was making contact with the top of the cup in the seating die. This allowed the bullet to cant slightly and not seat straight in the case.

RCBS is sending me a different cup, and if that does not work, then they will machine me a new cup for $20 or so. I just need to supply them with 3 bullets.

February 8, 2010, 07:41 PM	#1
bkhann Member Join Date: August 5, 2009 Location: Grand Rapids MI Posts: 98	Bullet Seating Question I loaded 100 9mm rounds today using Montana Gold 125 gr FMJ bullets, VV N-340 (4.5 gr) with a COL of 1.142". During a inspection of the finished loads I see that most of the bullets are slightly off center. If you roll the load on a flat tabletop this is quite obvious. I compared some moly/poly 9mm loads that I did some time ago, and those bullets seem to be better centered inthe cases. Has anyone experienced this and it it something to be concerned about? Is there possibly a problem with my equipment (useng Lee Turret Press with Lee dies)?

February 8, 2010, 10:22 PM	#2
88KEYS Senior Member Join Date: January 21, 2010 Posts: 145	Bullets I have loaded thousands of 9MM & 45 ACP; I did not check my load book on the OAL sounds ok, for that round. I think what you have done is set the bullet off center in the case; the problem could have been caused by several factors. I will just give you what I think based on my own learning by making mistakes, and now have been at it about 30 years. If you belled the case mouth off center more like an oval then round, and then started the bullet in the case for seating, it could have seated it off center. The other thing is the bullet could have been started off center with a slight lean to one side when placed in the case. The seating die should have centered it, but have seen rounds act in strange ways when loading. I would not shoot them as they are off center the bearing surface of the bullet will be greater on one side of the barrel. I would make sure all dies are set up properly and cleaned; seating dies can build up wax from lead bullets. Also your seating die does it have more than one stem, like Flat and Round Nose? The crimp what type applied, a die like the Redding Profile Crimp Die, will center a bullet and apply even crimp around the entire case. I think looking over the case and dies you should find the problem, it is a testing process. Good Luck

February 9, 2010, 02:13 AM	#3
wilkersk Member Join Date: April 2, 2009 Location: Western Washington Posts: 57	Yeah, 1) check your seating plug. RCBS seating dies come with 2 different plugs, 1 for flat points and HPs, the other for round nose. 2) Only flare (expand) your case mouths just enough so that the bullet will sit in the case mouth while you raise the ram up into the seating die. 3) always proof the 1st couple of your reloads in every batch by checking with a case gauge, or the barrel from your field stripped pistol that you're reloading for. Wobbly bullets suck for accuracy. If they don't strike the lanz of the barrel true, they won't be true when they leave the muzzle. Last edited by wilkersk; February 9, 2010 at 02:18 AM.

February 9, 2010, 03:07 PM	#6
88KEYS Senior Member Join Date: January 21, 2010 Posts: 145	Checking loads I will agree with the person that posted that you should chamber the rounds "in the gun" that will use them. This is a step I still do every time I load rounds, will fill a mag and cycle them through the weapon. Then closly inspect them for marks and indications the OAL is long and the bullet touched the rifiling. Using empty case's and loading is a good way to see what is going on, it is testing and finding what works. I have a cheap eye glass from the drug store works fine for inspection, make sure you have good light.

February 9, 2010, 02:59 AM	#4
colospgsAVID Senior Member Join Date: January 2, 2010 Location: Colorado Springs Posts: 188	I would be concerned. I don't have a whole lot of experience, but, I know concentric rounds equal accuracy. I've never had this problem before. I've loaded a lot of 9mm and damn they are concentric! I'm using lee dies in a rock chucker. Flare the case as minimally as possible, when you seat the bullet, after charging, hold it as parallel as possible. It should be a smooth feel as you seat the bullet. I am surprised it didn't feel off. Unless your bullets are at fault, I'd say it's technique.

February 9, 2010, 07:23 AM	#5
bkhann Member Join Date: August 5, 2009 Location: Grand Rapids MI Posts: 98	I took a look at bullet lengths this morning. The 124 gr 9mm FMJ bullets that are not seating straight are 0.581" long. 124 gr 9mm JHP bullets that I have are 0.575" long (I currently do not have any loaded. 124 gr hard cast lead bullets that I use are 0.575" long (these I have recently used and appear to be seated perfectly straight). With a VV N-340 powder charge 0f 4.5 gr, it appears that the longer FMJ bullets might be compressing the powder. I wonder if this might be contributing to the problem. I think that I will load a couple 9mm FMJ loads with no powder to see if the problen is a case fill issue................. Just re loaded test loads. The 0.581" bullet has some concentricity issues, the 0.575" bullets do not; so it appears that the problem is with using the slightly longer bullets. All 3 bullets are the same diameter. Go figure !!!!!

February 13, 2010, 08:17 PM	#7
hazfam2 Junior Member Join Date: February 7, 2010 Posts: 5	I think you might have your crimp die set a little to deep. I had the same problem until I did away with the crimp.l

February 13, 2010, 10:47 PM	#8
bkhann Member Join Date: August 5, 2009 Location: Grand Rapids MI Posts: 98	No, it turned out to be a problem with the seating die. It turns out that the nose of the bullet was making contact with the top of the cup in the seating die. This allowed the bullet to cant slightly and not seat straight in the case. RCBS is sending me a different cup, and if that does not work, then they will machine me a new cup for $20 or so. I just need to supply them with 3 bullets.