Bullet Seating Trouble

[TSpork]

Caliber:
308
Case:
Virgin Lapua
Bullet:
178 ELD-M
Press:
Forster Co-Ax
Die:
Forster Micrometer Seater

Loading precision is new to me, so there's a very likely chance I'm doing something stupid.

I trimmed the brass using my forster trimmer with 3-way cutter and power adapter. I trimmed them to 2.005, but some measured a couple thousands shorter. That was Saturday, I couldn't tell if it was my cheap calipers, so I bought some new Mitutoyos.

Fast forward to today. I'm just starting load development, so I'm loading up some rounds with varying powder charges. I used my Hornady length gauge and Hornady bullet comparator with the 8-30 bushing. When I push an ELD-M to touch the lands, I get a measurement of 2.310". I want to seat my bullets 0.020" off, so I want to set it so that my bullets measure 2.290" when using the bullet comparator.

I set my die up, and seat some bullets. I measure one, adjust the micrometer, and then measure again. Perfect. 2.290" I measure the next one and now it's 2.294" So I adjust my micrometer to seat 0.004" deeper and try again. It's now 2.290". As I go about seating bullets, I notice a ton of them are off. And sometimes I adjust my micrometer to match the setting and it doesn't seat it to the setting. For example: If I get a reading of 2.298" I adjust the micrometer to seat 0.008" deeper. Put the bullet back in the die and it might be 2.293". Adjust for 0.003" deeper and then it might be 2.290".

Here's an example of some readings of seated bullets off my comparator. This is without any adjustment of anything. These bullets were all seated one after another
2.277
2.288
2.276
2.277
2.283
2.281
2.275
2.290
2.274
2.284
2.290
2.281


The trimmer uses a pilot, and I noticed that sometimes the pilot was having a hard time going into the virgin Lapua brass. Could these issues be due to too much neck tension?

 

[XLR308]

Has been my experience that new Lapua brass has an excessive amount of neck tension so I run an expander mandrel through them before seating bullets.
I neck turn all of my new Lapua brass anyways so it's a step I'm allready taking.
Look up 21st century mandrel and dies or Sinclair if that's your flavor they are very reasonable on the prices.
The expander mandrel will yield about .001" neck tension and turning mandrel about .002` tension.
Another step you can add if you want to see less variation is sorting your bullets from base to ogive if you have the time and patience for that.

 

[Pilotscrappy]

As stated the seating die isn't the culprit. Most likely inconsistent neck tension especially with virgin brass

 

[Deleted member 10043]

You're also measuring with primers. Only measure CBTO on a case with a below flush primer. Once you have it where you want stop measuring so much.

 

[918v]

Comparators don’t measure the ogjive consistently. A workaround is to spin the round and measure several times. Make sure your primers aren’t sticking out as thetceill add to the length. Make sure the round is square to the comparator.

To make seating more consistent expand the necks with a mandrel first. Use Imperial dry neck lube.

 

[ShtrRdy]

Lots of good advice. Along with the excessive neck tension, new brass can result in a "sticky-ness" with the bullet.

One other thing to be aware of is the place on the bullet that the seating stem contacts is different than the place on the bullet that the bullet comparator contacts. On really good bullets , the distance between these two points will be very close, i.e. 0.001"

 

[Rocketvapor]

The length variation of over 0.020" is likely NOT due to high primers. How high do you guys accept?
This is with an ELD-M, an EASY to distort bullet. Seating and measuring from a highly tapered ogive will show variations from seating pressure, a stem that doesn't match the bullet profile, compressed charges, high neck tension, and to a small degree variations in the bullet shape between projectiles.

I would take a FEW bullets, measure to your lands.
Set up for your length and run a few through the press.
Adjust seating until you bracket the desired length a couple of thousandths, then run with it.
It takes more than measuring to get the ELD-M seated to a CONSISTENTLY REPEATABLE length.
Force is the likely culprit.
Got any closeup pics of the short and longs ones?
Using any bullet lube, like graphite or mica?

 

[918v]

The high primer variable needs to be eliminated. No it’s not causing a .020” variance but does contribute to it.

 

[TSpork]

Thank you guys for all the great advice. It truely helps

Has been my experience that new Lapua brass has an excessive amount of neck tension so I run an expander mandrel through them before seating bullets.
I neck turn all of my new Lapua brass anyways so it's a step I'm allready taking.
Look up 21st century mandrel and dies or Sinclair if that's your flavor they are very reasonable on the prices.
The expander mandrel will yield about .001" neck tension and turning mandrel about .002` tension.
Another step you can add if you want to see less variation is sorting your bullets from base to ogive if you have the time and patience for that.

I could tell that sometimes the trimmer pilot was harder to enter the case than others. These cases were not full length sized prior because my die is on backorder from brownells. This may be the issue

As stated the seating die isn't the culprit. Most likely inconsistent neck tension especially with virgin brass

Good to know! A mandrel may be the answer.

You're also measuring with primers. Only measure CBTO on a case with a below flush primer. Once you have it where you want stop measuring so much.

All the primers are below flush. All seated with a Frankford Arsenal handprimer. I was about to stop measuring, but decided to check a couple to be certain. Then I started seeing a wild variation, so I wanted to know what is happening. I think the variation I was seeing was way too high to be normal and didn’t want to accidentally seat one that would be dangerous.

Comparators don’t measure the ogjive consistently. A workaround is to spin the round and measure several times. Make sure your primers aren’t sticking out as thetceill add to the length. Make sure the round is square to the comparator.

To make seating more consistent expand the necks with a mandrel first. Use Imperial dry neck lube.

I’m pretty sure I was measuring accurately. I was using a hornady anvil base to give it something to sit flat against. And I would check each round several times to be certain, and I would always come up with the same numbers +/- 0.0005”. I would also rotate the round to make sure it was square.

I have lanolin. It sounds like I should pick up a mandrel for these new rounds. If I do, I’ll rub some lanolin on the mandrel every few cases. Would that work?

Lots of good advice. Along with the excessive neck tension, new brass can result in a "sticky-ness" with the bullet.

One other thing to be aware of is the place on the bullet that the seating stem contacts is different than the place on the bullet that the bullet comparator contacts. On really good bullets , the distance between these two points will be very close, i.e. 0.001"

Oh yes, I understand the point that a comparator touches isn’t the same as the seating stem. It’s a reference point

The length variation of over 0.020" is likely NOT due to high primers. How high do you guys accept?
This is with an ELD-M, an EASY to distort bullet. Seating and measuring from a highly tapered ogive will show variations from seating pressure, a stem that doesn't match the bullet profile, compressed charges, high neck tension, and to a small degree variations in the bullet shape between projectiles.

I would take a FEW bullets, measure to your lands.
Set up for your length and run a few through the press.
Adjust seating until you bracket the desired length a couple of thousandths, then run with it.
It takes more than measuring to get the ELD-M seated to a CONSISTENTLY REPEATABLE length.
Force is the likely culprit.
Got any closeup pics of the short and longs ones?
Using any bullet lube, like graphite or mica?

Gotcha. I didn’t want to run with it because the variation was so much. I could see hem being a little off here and there, but that seems like a lot. It seems like it would be that the necks are too tight on some of them.

No bullet lube was used. And I used the same force on all the seating. I allowed the co-Ax to cam over and even let it sit there for a few seconds to ensure it wasn’t due to any brass spring back. I was limited by how fast my chargemaster could throw charges anyways.

The high primer variable needs to be eliminated. No it’s not causing a .020” variance but does contribute to it.

All my primers were flush since I was using a handprimer that has a hardstop so they should be uniform. I can adjust how deep the hardstop stops at.

I’m heading to work now, but I can measure just how below flush they are when I get home if it helps

 

[TSpork]

21st Century Expander die and titanium nitride expander ordered

 

[spife7980]

Measure just the plain bullets. Do you have the same measurement discrepancies? If so group them into batches by similar lengths.

Seat one of those matching bullet batches, do the ogive seated length measurements match up or do they still have that much variance?

I too agree that its probably due to the differing amount sof neck tension. Brass that has been fired in your chamber will lead to much more uniform results. 50k psi has a way of expanding each and every piece to the identical chamber size

Doubt its your issue with a forster die but

The tip bottoming out before the ogive is in contact can cause these issues as well.

My money is still on it just being virgin brass. The mandrel will help if you dont mind taking the time to wait on it until you load up and shoot.
The virgin load wont match your fired brass load, probably a few tenths of a grain shy of where youll eventually end up with fired brass. But if you have a bunch of virgin to form then it might be worth it to make a load thats accurate for the first firing on those many pieces.

 

[Brux]

Take your Hornady bullet comparator and calipers and the box of bullets you are working with and just measure the bullets only. Bottom of bullet to ogive. If you get these erratic measurements measuring just the bullets then its the lot number of bullets that you are working with. if those numbers are all within 3 or 4 thou of each other then its not the bullets. If its not the bullets I would think the tip of the bullet is hitting the seating stem on your seating die before its hitting the ogive of the bullet. I have had to drill out several seating stems when seating polymer tip bullets for this reason. If your working with new brass always run your brass threw a die with a expander mandrel in it to correct dented case mouths and so on.

 

[TSpork]

Measure just the plain bullets. Do you have the same measurement discrepancies? If so group them into batches by similar lengths.

Seat one of those matching bullet batches, do the ogive seated length measurements match up or do they still have that much variance?

I too agree that its probably due to the differing amount sof neck tension. Brass that has been fired in your chamber will lead to much more uniform results. 50k psi has a way of expanding each and every piece to the identical chamber size

Doubt its your issue with a forster die but
View attachment 6997583
The tip bottoming out before the ogive is in contact can cause these issues as well.

My money is still on it just being virgin brass. The mandrel will help if you dont mind taking the time to wait on it until you load up and shoot.
The virgin load wont match your fired brass load, probably a few tenths of a grain shy of where youll eventually end up with fired brass. But if you have a bunch of virgin to form then it might be worth it to make a load thats accurate for the first firing on those many pieces.

Finally had time to measure my bullets. They don't have anywhere near that much variance as my seating depth
Here's the length of 10 bullets using that same Hornady comparator and anvil base.
0.7010
0.7005
0.7000
0.7000
0.7005
0.6985
0.6995
0.7000
0.6995
0.7000

Ya, right now I'm going to wait on the mandrel so I don't waste my time. If my bullet is bottoming out on my seating stem, wouldn't I see it deform my tip after seating them?

I only have 200 pieces of Lapua brass. So is it a waste to try and do load development with them since I'm going to have to change my load again anyways?

 

[TSpork]

Take your Hornady bullet comparator and calipers and the box of bullets you are working with and just measure the bullets only. Bottom of bullet to ogive. If you get these erratic measurements measuring just the bullets then its the lot number of bullets that you are working with. if those numbers are all within 3 or 4 thou of each other then its not the bullets. If its not the bullets I would think the tip of the bullet is hitting the seating stem on your seating die before its hitting the ogive of the bullet. I have had to drill out several seating stems when seating polymer tip bullets for this reason. If your working with new brass always run your brass threw a die with a expander mandrel in it to correct dented case mouths and so on.

Thanks for the reply! See my previous post. Also, I ordered some Redding dry neck lube so I can apply it while using the expander mandrel and again before seating my bullets

 

[spife7980]

Finally had time to measure my bullets. They don't have anywhere near that much variance as my seating depth
Here's the length of 10 bullets using that same Hornady comparator and anvil base.
0.7010
0.7005
0.7000
0.7000
0.7005
0.6985
0.6995
0.7000
0.6995
0.7000

Ya, right now I'm going to wait on the mandrel so I don't waste my time. If my bullet is bottoming out on my seating stem, wouldn't I see it deform my tip after seating them?

I only have 200 pieces of Lapua brass. So is it a waste to try and do load development with them since I'm going to have to change my load again anyways?

You might see it, you might not. You might be seeing it and not realizing. You can unscrew the seater dies in half and check it without losing the setting so long as you don’t mess with the micrometer.

I wouldn’t call it a waste, you’ll have a good load and good practice. Just expect it to change. You’ll find it can change over the life of the barrel depending on how things change after many explosions through the bore and components as loys change etc

 

[TSpork]

You might see it, you might not. You might be seeing it and not realizing. You can unscrew the seater dies in half and check it without losing the setting so long as you don’t mess with the micrometer.

I wouldn’t call it a waste, you’ll have a good load and good practice. Just expect it to change. You’ll find it can change over the life of the barrel depending on how things change after many explosions through the bore and components as loys change etc

Just checked right now. How can I tell if it's bottoming out? I don't think it is. When resting in the seater, it can wobble back and forth pretty easily

 

[Deleted member 10043]

Finally had time to measure my bullets. They don't have anywhere near that much variance as my seating depth
Here's the length of 10 bullets using that same Hornady comparator and anvil base.
0.7010
0.7005
0.7000
0.7000
0.7005
0.6985
0.6995
0.7000
0.6995
0.7000

Ya, right now I'm going to wait on the mandrel so I don't waste my time. If my bullet is bottoming out on my seating stem, wouldn't I see it deform my tip after seating them?

I only have 200 pieces of Lapua brass. So is it a waste to try and do load development with them since I'm going to have to change my load again anyways?

Measure the average and SD.

 

[TSpork]

Measure the average and SD.

So I got an average of 0.69995”(practically 0.7000”) with an SD of 0.000685”. Am I wrong in thinking that there’s no way that can be what’s throwing off my seating depths? I feel like that’s real consistent

 

[spife7980]

Just checked right now. How can I tell if it's bottoming out? I don't think it is. When resting in the seater, it can wobble back and forth pretty easily

Wobble back and forth: is it teetering on the very tip, back and forth, like a seesaw touching one side at a time? Or is it rolling around evenly and settling where it’s touching all around like a tennis ball on a cardboard paper towel tube?

Teetering and only touching one side will lead to discrepancies.
The wobble like a ball in a tube will naturally settle in to that complete ring diameter.

 

[spife7980]

So I got an average of 0.69995”(practically 0.7000”) with an SD of 0.000685”. Am I wrong in thinking that there’s no way that can be what’s throwing off my seating depths? I feel like that’s real consistent

The bullets don’t look like they are your problem. Let’s see how the mandrel and lube help.

 

[Precision Underground]

How hard you depress the arm on the press can give you wildly different depths, especially with new, thick necked brass. I always try to get into a rhythm when pulling the press down, paying close attention to how much pressure I am applying. You may have already said but did you chamfer the inside of the necks after trimming?

 

[Deleted member 10043]

Drill a little deeper into the seating neck to ensure the bullet tip is not touching. Had the same problem with the new .257 131 BJ ACE on a standard 25-06 seating die. I don't remember the exact drill bit other than it was about 3mm. I also chamfered the ID using a bullet and 600 grit paper to eliminate leaving a ring on the bullet. Doesn't take much to chamfer enough. Just a few times to take the edge off. I was too cheap to purchase a VLD stem.

 

[Brux]

First of all 25 thou difference in ogive measurements on the bullets is crap. And with your explanation it sounds like the tip is hitting in your seating stem before the ogive is making contact.

 

[Deleted member 10043]

Today I tried something completely different. A plain ol' Lee seating die slightly nudging the bullet to line it up, lowering the case to verify and then seat. Too simple.

 

[TSpork]

Wobble back and forth: is it teetering on the very tip, back and forth, like a seesaw touching one side at a time? Or is it rolling around evenly and settling where it’s touching all around like a tennis ball on a cardboard paper towel tube?

Teetering and only touching one side will lead to discrepancies.
The wobble like a ball in a tube will naturally settle in to that complete ring diameter.

It doesn't look like it's teetering and laying on one end, and seems to always settle in the same spot.

The bullets don’t look like they are your problem. Let’s see how the mandrel and lube help.

I think the lube and mandrel did the trick!

How hard you depress the arm on the press can give you wildly different depths, especially with new, thick necked brass. I always try to get into a rhythm when pulling the press down, paying close attention to how much pressure I am applying. You may have already said but did you chamfer the inside of the necks after trimming?

Ya, I always depress the arms slowly and let it sit in the bottom stroke for a couple of seconds. I'm using a cutter that trims, deburs, and chamfers at the same time.

Drill a little deeper into the seating neck to ensure the bullet tip is not touching. Had the same problem with the new .257 131 BJ ACE on a standard 25-06 seating die. I don't remember the exact drill bit other than it was about 3mm. I also chamfered the ID using a bullet and 600 grit paper to eliminate leaving a ring on the bullet. Doesn't take much to chamfer enough. Just a few times to take the edge off. I was too cheap to purchase a VLD stem.

I don't think it's touching, but that's good to know how to do it.

First of all 25 thou difference in ogive measurements on the bullets is crap. And with your explanation it sounds like the tip is hitting in your seating stem before the ogive is making contact.

I don't think it's hitting, although I may be wrong.

Today I tried something completely different. A plain ol' Lee seating die slightly nudging the bullet to line it up, lowering the case to verify and then seat. Too simple.

Interesting. Do the Lee dies hold the bullet with something other than a stem?



Thank you all for taking the time to help me out. I had a really busy week at work, and just got around last night to playing with my reloading setup.
So here's what I did:

I dipped the virgin lapua cases in the redding dry lube media, then ran them in the expander die.
Then I dipped them in the dry lube media again.
Seated a bullet.


I sat 1 bullet, then adjusted the die to seat at 2.290". I sat 5 bullets in a row and then measured. 4/5 measured 2.290" and 1/5 measured 2.2855"

It looks like this may have solved my problem. I pulled all the bullets that I had loaded in my last session, and proceeded to load them following my same process. The seating depths were not nearly as consistent, but that's probably because the brass has already been stretched out from seating once before. The brass that haven't had any rounds seated have been very consistent

 

[tscoz]

I always dry tumble new brass then run a neck brush through to get rid of the new brass neck “stickiness” and give more consistent seating depth.