Grendel case collapsing

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the_blacksmith

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Anyone else have issues with hornady cases collapsing when seating a bullet? I have a set of hornady custom grade dies (first set of those; all my other dies are Redding or RCBS), bullet seems not to matter; I’ve tried a few. I’ve tried dry lubing the case necks, lubing them with imperial wax, loading HBN coated bullets, chamfering the case neck inside…. About 1 in 5 just collapse rather than accepting the bullet. New brass, 1F, 2F now… still the same. Has anyone else had similar issues? The brass seems very thin; but not having used hornady dies before I’m not sure which component is more likely the issue. The seating stem is also not ideal, it seems, as it tends to mark the projectile. The force needed on the press seems normal/average compared to 6.5cm that I also load for. I don’t have marks on any CM projectiles (Redding comp seating die).

Ideas?
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Are there any marks on the case neck or mouth that could indicate there is a clearance problem inside the die? Maybe the die is undersized and some of your case necks are overly thick?

I had a Redding 22 PPC die that had very tight tolerances and would collapse the necks when I used Lapua brass. The Lapua was thicker than the Sako brass I was previously using. I had to ream the ID of the die about .005” to avoid the problems you’re having.
 
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Would it happen to be a 6 Grendel sizing die mixed in instead of a 6.5? What's the sized brass neck diameter?
 
Hate to ask, but is the die set too low and the case is getting crimped as the bullet is being pushed into neck? (has happened to me)
 
Thinking out loud here…

The entire shoulder looks to be collapsed in on itself. That’s a lot of movement of the press ram to cause that much collapse. It isn’t happening at the end of the stroke but near the point at which the case neck is entering the top portion of the die. My money is still on a clearance issue of sone kind. The infrequency of the problem is somewhat of a head scratcher though. I’m assuming the same lot of brass is being used.
 
possible issues

Brass was annealed too soft in the neck area

neck expander die is undersize

you are using new brass
brass could be too clean ( you can tumble the brass using car polish with your cleaning media) .....wax makes it grip less

have you checked bullet diameter ?
 
I was loading 6.5x55 once and grabbed a box of 140gr SSTs off the shelf... turned out they were .277" and I only realized the mistake after seating one. It only expanded the neck of the brass and reinforced the importance of reading labels thoroughly. Given that your brass looks normal other than the collapsed shoulder, I'd be examining the possibility of size discrepancy first.
 
I’ve tried several different weights and brands of projectiles; 100gr lapua scenar, 120gr eldm, 123gr amax, and a few others as well. I have only .264 and .308 projectiles on the bench, so it’s not a .277 accidentally being used. Bullet diameter is good i think; plus I’ve used the same bullets in my 6.5cm and they are fine. I can’t see any marks on the necks to indicate that the seating die is too tight, and the post sized neck inner diameter is .261. A bit tight I suppose; more than my CM but I’ve loaded other cases that tight and never had this issue. To my eye, this brass seems very thin; almost like 44-40 or something. I haven’t annealed these cases yet, and from the failure rate on this batch of brass it’s looking like I won’t get the chance…

I have also in the past set the body of the die too low and crimped cases, but in every case I’ve done that in the brass only buckles a little; just enough that it won’t chamber. Honestly, I’m leaning towards it being a dies issue. I’ve set and re-setup this die quite a few times and nothing changes. Doesn’t seem to matter if the cases are lubed inside or not. Well, that’s not quite right. Once the bullet is sliding in to the neck, the lube makes a difference. But there still seems to be the same or similar rate of shoulder collapse. The case neck being chamfered inside also doesn’t seem to make a difference.
 
I have multiple brands of dies and have screwed up several times when I presume that I know how to set up the particular brand I am using - I have two sets of "Hornady Custom Grade Dies" here and just read the set up procedure for that seating die - one set I have used once previously, and the other is still sealed shut - once again, another version and is different from the RCBS and Lee Precision set-up sequence. Maybe want to review that - was not really clear to me from earlier posts if you had been following Hornady's steps for setting it up?
 
Potashminer said:
I have multiple brands of dies and have screwed up several times when I presume that I know how to set up the particular brand I am using - I have two sets of "Hornady Custom Grade Dies" here and just read the set up procedure for that seating die - one set I have used once previously, and the other is still sealed shut - once again, another version and is different from the RCBS and Lee Precision set-up sequence. Maybe want to review that - was not really clear to me from earlier posts if you had been following Hornady's steps for setting it up?
Click to expand...

You know, that’s a good point; I did read the directions on it when setting it up initially, but not again after that. Most likely it’s operator error…
 
Hard to explain why only happening every few cases and not every time - sort of have to start at beginning, I guess, and eliminate everything possible? I have collapsed cases from not having dies set correctly - but that was every one that I tried. And from trying to reform to another case with smaller neck and taking too big a "step". As per Richard Lee manual, he wants about .002" expansion to the neck when a bullet gets seated into it - so .002" "stretch" - inside of sized case neck to be .002" smaller than bullet diameter. So, would think the amount of force required to do that would not be collapsing cases?? Since forever, I "chamfer" case mouths - as in "break" that sharp inside edge at case mouth - on factory new and when trimmed for length, but that is all - I doubt that I take out 25% of the case mouth wall - trying for much less than that.
 
Potashminer said:
Hard to explain why only happening every few cases and not every time - sort of have to start at beginning, I guess, and eliminate everything possible? I have collapsed cases from not having dies set correctly - but that was every one that I tried. And from trying to reform to another case with smaller neck and taking too big a "step". As per Richard Lee manual, he wants about .002" expansion to the neck when a bullet gets seated into it - so .002" "stretch" - inside of sized case neck to be .002" smaller than bullet diameter. So, would think the amount of force required to do that would not be collapsing cases?? Since forever, I "chamfer" case mouths - as in "break" that sharp inside edge at case mouth - on factory new and when trimmed for length, but that is all - I doubt that I take out 25% of the case mouth wall - trying for much less than that.
Click to expand...


Yes, these are all chamfered. These cases have had about the same fail rate on every loading since new; the 100 new cases I got are now down to about 60-65 on the third loading. The bullets I’m using are also low drag bullets with a very pronounced boat tail profile, so they are started before there is any tension on the case neck.
 
the_blacksmith said:
...." the post sized neck inner diameter is .261. A bit tight I suppose..."
Click to expand...

That final 0.261 neck size may be a bit tight if that lot of brass is somehow softer than it should be. After 2 firings, and 2 full length resizings, one would think that neck and shoulder should harden up, so maybe that brass is extra soft?

I use a Sinclair neck expander mandrel die as the final step before seating. Expander mandrel at 0.263 is 1 thou smaller than the 6.5 bullet (0.264), and this final step seems to make a difference for relieving some neck tension from the rather aggressive sizer dies that I have. Depending on how hard the brass is, there is spring back that can be felt when the case pops off the mandrel, so final neck size is less than 0.263 in my brass, but its wider than what the sizer die made it. (I don't have bushing dies to have better custom control over neck tension, but plan to obtain some bushing dies soon). Before using the expander mandrel die I lube the necks with Redding dry lube graphite.

Maybe if you could expand first before bullet seating, it might help. If the lubed expander collapses the necks, that is one more clue to help in this mystery.
 
Do you have any other brass to try? Keep us posted on setting up the dies again. I don't have any experience with Hornady dies and have 2 sets sitting here so I am following along to see if any tips come in for them.

As said above the expander ball might not be sizing enough when you pull back through. Try the 6.5CM expander die and see what the neck diameter does.
 
This is common with Hornady dies the floating part of the seating die gets misaligned, I’ve had it happen with just about every Hornady seating die I’ve used. Take it apart and clean it and then pay attention when you seat.
 
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