Bullet Seating Runout

[mtJim]

It's hard to tell from the pics, but it looks like some irregularity in the shoulder like the seating die is pinching the shoulder. Back the die off 1/16-1/8 of a turn then re-adjust your seating depth.

The seating die is backed off the shellholder 1/4 to 1/2 turn. There is no contact with an empty case and the seating die. I am using a Lee factory crimp die as a separate final step.

Has the cases been trimmed too length , you could be too long, causing the seater too bottom out on the neck of the case , at the bullet junction.

Cases are all trimmed to 2.539" (Barnes Manual)

Follow Up on#25~#27 above. Hard to tell, but it also looks like the case neck is not quite square. Kinda like it was trimmed at a slight angle.

Hopefully the case mouth just looks crooked from a bad picture, will definitely look into that.

Thanks to everyone, I appreciate the conversation. I've ordered some pin gauges to investigate the donut a little more closely, and will check the case mouths for square. Travelling for work this week so hopefully have some results this weekend.

 

[mtJim]

Got some more testing done this morning. A .273 pin gauge slid completely through the neck of all prepped cases. The .272 fit easily, .273 snug, and .274 wouldn't go. I could not find any sign of a donut. Also, could not find any irregularities in the case mouths, at least to .0005.

I tried loading another round and seating a little, then turn, seat a little then turn. This one would stick every time the bullet was fully into the stem, last week it was only at the end of the stroke that it would stick.

My ideas now are to get a mandrel and lessen my neck tension for seating, since I am using a Lee factory crimp die anyways. And if that doesn't help then try bedding the seating stem. I guess all this after just shooting it first, make sure I am not trying to create a problem where there aren't any in the first place.

It's just driving me crazy after I've done the same thing for several reloads through load development, now things are different. The only thing that has changed is annealing.

 

[Barrelnut]

Did you ever try a different bullet? Maybe something that's not a VLD style. That could rule out, or point the finger at, a lot of things especially this odd sticking of the bullet in the stem.

 

[RockyMtnMT]

Your neck tension with the softer annealed brass might be a bit high causing the shoulder to slightly collapse making the neck wider at the neck junction than it is at the case mouth. This would allow the bullet to wobble in the neck causing the run out. I agree with trying a bit less neck tension.

 

[mtJim]

Did you ever try a different bullet? Maybe something that's not a VLD style. That could rule out, or point the finger at, a lot of things especially this odd sticking of the bullet in the stem.

Both a Hornady Interlock and a Nosler Accubond have done the exact same thing with the bullet sticking in the stem.

Ordering a .2755 mandrel and see if that helps.

 

[Rflshootr]

Sounds like you have pretty heavy neck tension. I run .002 and no more than .003 max. The expander size that you picked sounds good. That should help your issue. While you're at it, I'd also measure the expander in the sizing die. It's probably undersize. Should be about .001-.002 under bullet diameter. If it is undersize, any reputable die manufacturer will replace it if you give them a call.
Things still don't look right to me in the picture. Maybe it's just a bad picture.
I see a step at the neck/shoulder junction, where there should be a .151 radius, what looks to be a deformed shoulder, and circumferential scratches toward the top of the body. Again, maybe it's just the picture.

 

[mtJim]

Sounds like you have pretty heavy neck tension. I run .002 and no more than .003 max. The expander size that you picked sounds good. That should help your issue. While you're at it, I'd also measure the expander in the sizing die. It's probably undersize. Should be about .001-.002 under bullet diameter. If it is undersize, any reputable die manufacturer will replace it if you give them a call.
Things still don't look right to me in the picture. Maybe it's just a bad picture.
I see a step at the neck/shoulder junction, where there should be a .151 radius, what looks to be a deformed shoulder, and circumferential scratches toward the top of the body. Again, maybe it's just the picture.

It is plenty of neck tension, .004 right now. I didn't even measure prior to annealing, since there were no issues and it was looking good and shooting good.

I haven't yet shot these few reloads since annealing and reloading, but I know I didn't have this sticking issues prior to annealing/resizing/prepping. I usually don't have my dial indicator setup on my concentricity gauge, but I will spin a loaded round just for visual. These latest reloads have a visible wobble, something I never noticed before.

It's just a bad picture the wonky looking stuff. The shoulder is a smooth radius, no step. The most likely cause of the scratches is from having the rounds previously loaded and stored in the MTM ammo box bullet down. I tore those rounds apart and resized with the new chamber. Also since got new ammo boxes.

The bullet is definitely misaligned, making the case mouth look out of square. I couldn't measure anything out of square on the mouth, at least to .0005.

I am with @RockyMtnMT, my thinking is the softness of the freshly annealed brass and the high neck tension is causing the bullet to wobble. And hopefully this will also resolve itself after the first firing.

 

[Rflshootr]

Ok. There is some new light on the subject which brings some new questions. Did you clean the brass where there is no carbon left in the neck during your annealing/prep process? Residual carbon in the neck acts as a lubricant. If so, did you lubricate the inside of the neck before seating bullets? I also agree with RockyMtnMT. One thing you can try while you wait for the expander mandrel is to resize 1 case in the die about 2 or 3 times. The squeezing and expanding of the neck will slightly work harden it. Then try seating a bullet making sure there is a small amount of lube on the inside of the case neck. A nylon brush with some case lube on it works well.

 

[59FLH]

mtjim: The seating die is backed off the shellholder 1/4 to 1/2 turn

This is not the correct way to adjust a Redding BN seating die.

 

[mtJim]

Ok. There is some new light on the subject which brings some new questions. Did you clean the brass where there is no carbon left in the neck during your annealing/prep process? Residual carbon in the neck acts as a lubricant. If so, did you lubricate the inside of the neck before seating bullets? I also agree with RockyMtnMT. One thing you can try while you wait for the expander mandrel is to resize 1 case in the die about 2 or 3 times. The squeezing and expanding of the neck will slightly work harden it. Then try seating a bullet making sure there is a small amount of lube on the inside of the case neck. A nylon brush with some case lube on it works well.

I do wet tumble so necks are completely clean. I have tried putting some imperial on the drive bands of the bullet, with no improvement.

I have resized some old brass I have that hadn't been annealed with this new batch of Norma brass. It was wet tumbled. They resize smooth and a bullet is seated normally with no sticking.

That is a good idea sizing and expanding a few times, I will try that.

 

[Rflshootr]

Putting lube on the bullet doesn't work. The lube wipes off as it goes down the dry neck. You need the entire neck to have lube so as the bullet goes down, the leading edge sees fresh lube all the way. The 2 soft metals are starting to gall against each other from the friction of the tight neck tension. As the brass gets work hardened, it becomes slightly slicker and you are getting by with it, but not on the freshly annealed necks.

 

[mtJim]

I broke the rule of only changing one thing at a time, but in this case I think all three are part of the solution.

I ordered and received a .2755 mandrel. I removed the decapping stem and expander button from my FL sizing die, and run the cases through the bare sizing die. Then used the mandrel to set the neck tension. I added imperial to the inside of the case mouth, and rotated the case three times while seating the bullet.

Average runout on the bullet is now .002-.003. A few still go up to around .005, but way better than the .008-.010 that I was seeing before.

Thanks everyone for the suggestions and ideas, much appreciated.