"Houston, we have a problem"

[Hoot]

Okay, So I loaded my new, prepped brass a week or so ago and shot them up. After meticulously prepping them for the next experiment, I go to seat some of the Nosler 120gr BT's I used the first time out and after going in about half way to the proper COL, they get increasingly harder and then the case collapses into itself. Figuring it was a fluke, I repeated the process on the next round and it worked fine. The next one caved in and I stopped and checked the mouth ID on all the brass. They ranged from .2615 to .2618. The bullets are all .2635. The original brass were .2620-.2623 ID. I had already burnished the inside of the necks with a rotating bore brush after I gave them their first tumble and before decapping, to reduce abrasive wear on my decapping ball from powder residue. They had not grown longer after their first firing and I did not need to trim them back to 1.515, but I touched up the inner and outer lips to be safe. Crushed another one first try. It does not feel like they are hanging on the lip and I doubt I would have gotten them half way in before they seized if they were.

My tapered decapping ball measures .2628 and passes through the resized necks with only a modest resistance. They obviously expand to .2628, but the spring-back returns them to .2615. I annealed two of them and repeated the step. They returned to .2618 and upon seating a bullets into them, the first one just made it and the second collapsed like the others before.

Anyone with an accurate micrometer who can measure their decapping ball? I'm suspecting mine may be slightly undersized for the spring-back. My chamber is a .300 neck one and spent brass mic at .299 OD / 2.69 ID. Resizing pushes them back down to .288-.289 OD with an ID of .257-.259 before the decapping ball goes through. Do I need to relieve a mil or two off the neck OD resizing. That's a lot of work to do correctly, but you do what you have to do.

FWIW, I'm not learning reloading. I've been reloading about 30 years and am up to 15 different rifle/pistol calibers as well as 12ga shotshells. This is the first time I've encountered this other than a few .300 Win Mags many years ago.

I am using Hornady New Dimension Dies.

Thanks,

Hoot

[Bill Alexander]

This is not a new problem in reloading although I am surpised at the measurements from the Hornady dies. I have never seen anything from them before though so have not checked.

The occurance manifests in any case with a sharp neck angle and is commonly created when the case and the bullet are excessively cleaned. The quick dirty solution is to rub a little lanolin onto your hands and then roll all the bullets between them. The very slight coating makes the neck collapse go away.

the best way is to leave the bullets on a radiator over the winter and let them tarnish. This not only helps seating but also uniforms the bullet pull and engraving forces.

Bill Alexander

[thinder]

I had this problem with a 25 Gibbs once. It sounds unrelated to my problem but maybe it will stir ideas.

My problem was that I had the seating die body too low (being a wildcat i guess you can do that) and the case neck would get pinched between the bullet and the die body during seating and dig into the side of the bullet. Being that the case was already thin at the neck from fireforming, i would just invert itself.

But like i said, Probably not the problem but maybe it will give you some ideas.

[Hoot]

This is not a new problem in reloading although I am surpised at the measurements from the Hornady dies. I have never seen anything from them before though so have not checked.

The occurance manifests in any case with a sharp neck angle and is commonly created when the case and the bullet are excessively cleaned. The quick dirty solution is to rub a little lanolin onto your hands and then roll all the bullets between them. The very slight coating makes the neck collapse go away.

the best way is to leave the bullets on a radiator over the winter and let them tarnish. This not only helps seating but also uniforms the bullet pull and engraving forces.

Bill Alexander

Wow Bill! My fastidious ways may have come back to haunt me. I'm so hung on adequate neck tension that I chuck each case in a lock-stud, spin it up and scrub the inside of the necks with powerful degreaser on q-tips. I have always labored under the assumption that any contaminant inside the case, especially the neck was a bad thing because it introduces uncontrolled variables into the equation. Ditto on the bullets. I so wanted to get accurate initial load results with this new caliber, that I gave the cases an extra dose of touch labor. I guess the old adage from music "Less is more" applies here.

Thanks for the DUH! moment.

Hoot

[Hoot]

I had this problem with a 25 Gibbs once. It sounds unrelated to my problem but maybe it will stir ideas.

My problem was that I had the seating die body too low (being a wildcat i guess you can do that) and the case neck would get pinched between the bullet and the die body during seating and dig into the side of the bullet. Being that the case was already thin at the neck from fireforming, i would just invert itself.

But like i said, Probably not the problem but maybe it will give you some ideas.

That is a valid concern. I had set up my seating die by screwing it in with a case in the holder and the ram engaged, until I felt the crimping cone touch the case. I then unscrewed it one turn and locked the ring to guarantee there would be no crimp imparted. That's what Hornady's instructions said to do for a no-crimp seat.

Still would like to hear what other folks measure for their decapping ball diameter. I did a sanity check on my .260 Remington die set decapping ball and it was .262 also.

Thanks,

Hoot

[rasp65]

Hoot this is the same problem that I had with 5 out of 100 brand new ALEXA cases. The first 50 had no problems. I was loading 120 SMK's that I had treated with HBN a dry lube. Like you I have never encountered this problem in 30+ years of reloading. Do yours look like this? [ATTACH=CONFIG]26[/ATTACH][ATTACH=CONFIG]27[/ATTACH][ATTACH=CONFIG]28[/ATTACH]

[Rapidrob]

I've been reloading since 1963. What you describe is either a die not bored properly or your brass is too thick at the neck. I have yet to see a brand of dies that does not have a problem from time to time.
The most common problem is the brass. Remove the decapper/neck expanded and size a fired shell. What is the neck diameter after sizing? ( inside/outside)
Back your die off three full turns. Size a fired shell. Can you see a very distinct ring where the neck has been sized? Is it measuring too small on the inside?
Measure your bullets. Are they .264? ( or close)

[Hoot]

Hoot this is the same problem that I had with 5 out of 100 brand new ALEXA cases. The first 50 had no problems. I was loading 120 SMK's that I had treated with HBN a dry lube. Like you I have never encountered this problem in 30+ years of reloading. Do yours look like this? [ATTACH=CONFIG]26[/ATTACH][ATTACH=CONFIG]27[/ATTACH][ATTACH=CONFIG]28[/ATTACH]

Ding Ding Ding!

Looks like you snuck into my man cave and photographed my cases, aside from the color of the BT.

I didn't want to mention that variable so as not to cloud the discussion. This lot of bullets mic at .2635, but like rasp65 mine are HBN shot plated and mic at .2638. Both being less than .264.

I'm at work now, but if it adds to any understanding, I have a once fired, unsized piece here with me. The neck mics at .269 ID / .299 OD, so one would assume the walls are .015

IIRC, the resized once fired brass at home, minus the expander pass mic at .260 ID / .290 OD and new out of the box they were .257 ID / .287 OD.

I realize I would have been better served by a .295 neck chamber, but .300 was what I got and it's what I have to live with.

Thanks for all the good input guys.

Hoot

[rasp65]

Hoot you did not say what type of brass it was you were using. In my case I checked everything I could as you did. I think the brass I had was over annealed giving it too soft a shoulder because I did not have any problems like this in the previous 1K rounds I had loaded.

[VASCAR2]

I crushed a couple of cases trying to seat bullets and I attributed it to varying case lengths. Since I started sorting and trimming my cases I haven't ruined any brass cases.

[Hoot]

The brass are Hornady. I bought two boxes from different lots. If I can't resolve this issue with the batch I'm working from, I'll begrudgingly scrap them and see how I fare with the other box. I have a few ideas to pursue yet.

Hoot

[LR1955]

Hoot you did not say what type of brass it was you were using. In my case I checked everything I could as you did. I think the brass I had was over annealed giving it too soft a shoulder because I did not have any problems like this in the previous 1K rounds I had loaded.

Rasp:

I believe you are right that the brass was improperly annealed. Honestly, it has never happened to me with any cartridge. If the seating die was cut too short, every single piece would get crushed.

Good luck getting any brass manufacturer to admit it though.

LR55

[rasp65]

I guess I will be happy that it only happened to 5 out of 100. I think I will pull them apart and try to blow them out with the cream of wheat method.

[Hoot]

I'm dead on my feet, but suspect I have found the problem. I suspect it is a resizing issue and I will explain in depth tomorrow with images.

Hoot

[Hoot]

I had a lengthy presentation with images shot through my B&L stereo micro-viewer, etc, but decided to spare you all.

When I set up my sizing die, I set it to engage the top of the shell holder with a half additional turn for tension. When sizing my new brass, I could feel it bumping the shoulder ever so slightly and decided that would be a good starting point until after they were all fire formed. All the bullets, both plain and HBN coated seated fine, shot fine and cleaned up nicely for the next pass. With the same amount of bumping the next time around, I created a minute narrow spot where the neck meets the shoulder that could only be seen under the micro-viewer. It's location was consistent with the amount of insertion depth of the bullet when the seizing occurred. With my next box of brass, I will screw in the sizing die to the point where it only touches the shoulder, but does not exert any significant pressure on it and try again. Someone asked what the sized OD of the neck was without the expander running through. That figure is .285, which I feel is really small for a .300 neck chamber. Now add the expander and it goes back up a little to .289, which I also feel is tighter than optimum, but that's the die I have. That OD yields an ID of .2615. I'd rather that be more like .262, but I can't see the difference causing enough friction for the shoulders to crush, but then there's a lot I have to learn yet. I may have exacerbated that with my fastidious treatment of the inside of the necks as well. Live and learn. I will report back after the weather returns to tolerable and I get out again.

Hoot

[bwaites]

I want all the pictures!!

Its a teaching process for all of us!

[Hoot]

I want all the pictures!!

Its a teaching process for all of us!

Here's an excerpt from a more lengthy post paralleling this one over on beyond556.com:

...snip...

In the next image, you can see the narrowing imparted to the new brass after sizing them:



Back home, I tumbled all the brass, inspected them for any damage and burnished the powder residue out of the insides of the necks. I set one aside as a reference and ran the remaining 47 through the resizing/decapping process again using the same setup and procedure as earlier.

When I went to load my next experiments, that is when I ran into the problem already explained. Close examination of the reference cases revealed what may be the problem.

In the next image, you can see a new case alongside a fired, unsized case. The ring did not "iron out" from shooting.



Sizing the fired cases again exacerbated the ring to the point where when I went to seat my next experiments they seized when the bearing surface of the bullet reached that ring. I doubt fire forming those damaged cases will bring them back to normal, So I'm writing them off as a costly lesson.

The next batch will be initially sized by adjusting the sizing die down to where it just touches the shoulder and locking it down there as opposed to where it firmly engages the shell holder, a turn further down from that point.

Thanks to everyone who responded. Hopefully, you will not hear of this problem reoccurring as I learn the do's and dont's of reloading this caliber.

One person asked what the resulting OD neck size was if I just sized without the decapper. That figure is .2855, which I personally feel is a bit much for a .300 neck chamber, but that's what I got with the Hornady die. I am ever so slowly lapping the neck portion of the die open to more like what the new brass come in at. That being .2883. Doing so may make it easier for the expander to create an ID closer to .262. I am going slow, having spent the entire evening getting it up to .2863 when I quit for bedtime, which is now past. 04:30 comes pretty early. More tomorrow evening...

Hoot

[bwaites]

So if I understand you, you believe that there is an inside ring, a doughnut, formed by resizing?

This happens with resizing brass when you neck down, say when people resize 7.62x39 to Grendel, but I've not heard of it happening with Grendel brass.

People solve this by inside neck reaming the brass.

[Hoot]

Bill, this defies my core understanding of metallurgy. It appears not to be a dougnut example A.
It looks like buckling example B.




Makes no sense to me at all. Bear in mind it is extremely subtle. IE I can't feel it on the inside with a dental pick. I've checked and re-checked and it is not a manufacturing mistake on the inside of the die. The die transitions from the shoulder to the neck perfectly.

Hoot

[Rapidrob]

Thank you for all you photo's and measurements. you nailed it. Your sizing die is the culprit. Just because dies are new and expensive, that does not make them perfect. Many times over the years I've had to send dies back. The reamer used to cut the die was: Too worn,too small,chattered,off center,etc.
your on the right track with honing out the neck. My general rule of thumb is to never move the shoulder back once it has been fired out of my rifle. My dies are made to small base size and neck size only. It seems to work well in my semi-auto rifles.