Vacuum seal in seating stem?

[darth_ritis]

I'm loading some 88gr ELD-Match bullets using a Redding competition die with the VLD seating stem. I switched seating stems because the original stem would damage the bullets.

My last batch of handloads with this combo didn't have this problem, but this loading session I'm having issues with the seating stem getting a really strong grip on the bullet. So much that either the bullet doesn't end up seated as deep as the die is set for or the stem grabs the bullet and won't let go at all and I have to disassemble the die to separate them.

Is this combo of bullet and seating stem susceptible to vacuum seal problems or any other galling issues? Is there any alternative besides going back to the original bullet-deforming seating stem?

 

[KZP]

How much resistance are you getting when seating into the case?

 

[darth_ritis]

That depends. I have a .249 bushing that seems to result in the seating die crushing the cases. I didn't have a problem with that bushing before, but now that I've primed 100 cases and started seating I've had to toss a half dozen crushed cases. I tried to resolve this with my K&M .224 expanding mandrel (because the cases are primed now) which resulted in a .251 OD and only .001 neck tension. That's part of the problem here, which I'll probably order a .250 bushing to fix, but I've never seen a seating stem grab onto a bullet so tightly that I have to disassemble the die to separate them. I'm thinking there's a vacuum seal being created perhaps?

 

[Rocketvapor]

"either the bullet doesn't end up seated as deep as the die is set for or the stem grabs the bullet and won't let go at all "

It's not vacuum. The most you could get with the seating stem with a complete vacuum would be less than 1/2 lbf.

Picture of one of the stuck/unstuck projectiles?

This setup worked before? But not this time?
Chamfer?
Same cases (neck thickness)?

My guess is the seating force is enough to deform the jacket, push the seating stem down and mushroom the jacket in the seating stem.
Doesn't take much if the stem is not a real good match to the ogive. The tipped ELD might be just enough different from a VLD to jam.

 

[darth_ritis]

Picture of one of the stuck/unstuck projectiles?

This setup worked before? But not this time?
Chamfer?
Same cases (neck thickness)?

My guess is the seating force is enough to deform the jacket, push the seating stem down and mushroom the jacket in the seating stem.
Doesn't take much if the stem is not a real good match to the ogive. The tipped ELD might be just enough different from a VLD to jam.

I'll load some more in a little while, and take some pictures.

Yes, this setup with the .249 bushing and VLD seating stem worked without issue last batch.

Necks all chamfered and deburred with Lyman VLD chamfer tools.

The bullets I extracted from the seating stem seemed to have no damage, whereas the original seating stem would press a very obvious ring into the bullet between the ogive and tip and would actually elongate the bullet. I'm seating just within mag length and these bullets would elongate to the point of not working in the mag. Pic:

 

[Rocketvapor]

Ouch
That's some ugly bullets
Reflections probably make them look worse than they really are.
You might end up sending a couple off and getting a 'Custom' seating Stem.

I'm using a Hornady AMAX seating stem and still get a little imprint on the bullet.
I size with a Redding body die and neck with a Lee collet die.

 

[918v]

Way too much seating pressure. Use more Imperial Dry Lube on the necks.

 

[darth_ritis]

I was just making another attempt to load these 88s after swabing out the inside of the seating stem. One loaded OK, one loaded but took multiple attempts, then this was the third one. The mark on the bullet cannot be felt and can only barely be seen by the naked eye. The camera and flash made it show up a lot better. I wouldn't consider it a significant issue, especially compared to the damage done by the old seating stem.

I'm done. Moving on to 80gr Bergers.

 

[Rocketvapor]

I know. It's hard to get a picture of something curved and shiny that looks like real life.
Like the scratches on the driving section of the bullet. Flash shows them up really well.

 

[spife7980]

What is the outside diameter of a loaded round?

Does a bullet pass freely though the seating stem sleeve?

Can you measure the inside diameter of the seating sleeve with the pointy part of your calipers? To see if it is enough or if you will have an interference fit with your round inside the sleeve.

I have a hard time thinking that your bushing being .001 too small, alone, is enough to create a difference in force that you’re getting these issues. Take the die apart and try the individual components in them to see if there is any hanging up.

 

[darth_ritis]

What is the outside diameter of a loaded round?

0.252"

Does a bullet pass freely though the seating stem sleeve?

Yes.

Can you measure the inside diameter of the seating sleeve with the pointy part of your calipers? To see if it is enough or if you will have an interference fit with your round inside the sleeve.

I get 0.224".

I have a hard time thinking that your bushing being .001 too small, alone, is enough to create a difference in force that you’re getting these issues. Take the die apart and try the individual components in them to see if there is any hanging up.

The bushing size goes to the neck tension and seating tension, which was causing crushed cases. When I tried to fix that by re-running my expander mandrel through, I started having too little neck tension. That's when the seating stem problem started, but I don't believe light neck tension alone would cause this seating stem issue. I've loaded light neck tension loads before and have never had this problem.

The die components seem to move smoothly, I've cleaned them and oiled them very lightly.

 

[bax]

Pulling bullets out: it looks like the seating force is very high, the force expands and deforms the bullet into the seating stem and when you pull the loaded round out of the seating die, the deformed bullet is held in the stem.

High seating force: Could the neck be too long (or the die screwed in too far), the die is crimping the neck onto the bullet and increasing the force needed to seat?

Try running a case into the seater without powder or bullet then inspect the case mouth. If it is crimped then back the seater die out and screw the seater stem in further.

I assume that you are not using a compressed charge that requires high force to get the bullets in far enough to fit your mag.

Bullet seating force should be insignificant. Once you get the seating force back to normal, the bullets should not deform into the stem and the problem should vanish.

What am I missing?

 

[darth_ritis]

Pulling bullets out: it looks like the seating force is very high, the force expands and deforms the bullet into the seating stem and when you pull the loaded round out of the seating die, the deformed bullet is held in the stem.

High seating force: Could the neck be too long (or the die screwed in too far), the die is crimping the neck onto the bullet and increasing the force needed to seat?

Try running a case into the seater without powder or bullet then inspect the case mouth. If it is crimped then back the seater die out and screw the seater stem in further.

I assume that you are not using a compressed charge that requires high force to get the bullets in far enough to fit your mag.

Bullet seating force should be insignificant. Once you get the seating force back to normal, the bullets should not deform into the stem and the problem should vanish.

What am I missing?

With only .001" neck tension, the seating force is low. There's actually more force required to lower the press after seating - assuming this is where the die is stuck and the press is now pulling the bullet back out of the case. And there doesn't seem to be any contact between the case neck and the die as far as I can tell.

I haven't had an issue with the Bergers, so it's just this 88gr ELDM that the seating stem doesn't like.

 

[spife7980]

Could just be a super tight seal and the perfect storm of conditions. If other bullets that you’ve tried them that seems like the easiest solution. Does it suck in tight with just your finger pressing the bullet into the stem? Stem isn’t cracked or warped is it? I had a forster stem flare open over time (but not cracked) and would stick in the die, the new stem they sent me fixed it.

 

[bax]

With only .001" neck tension, the seating force is low. There's actually more force required to lower the press after seating - assuming this is where the die is stuck and the press is now pulling the bullet back out of the case. And there doesn't seem to be any contact between the case neck and the die as far as I can tell.

Based on the photos it appears as though the bullets are deformed. It would take a lot of force to deform those bullets. If down-stroke seating force is low, at what point in the cycle do you apply the force that deforms the bullets? Or - perhaps I misinterpreted the photo and the bullets aren't deformed. Could that be true?

 

[Deleted member 10043]

 

[Rocketvapor]

Light marks on the ogive that causes small variations in seating depth is one thing. Distorting bullets and significant OAL variations can be caused also by compressed charges or case donuts. If changing to the Bergers eliminates the problem then it just might be a mismatched stem.

 

[darth_ritis]

Based on the photos it appears as though the bullets are deformed. It would take a lot of force to deform those bullets. If down-stroke seating force is low, at what point in the cycle do you apply the force that deforms the bullets? Or - perhaps I misinterpreted the photo and the bullets aren't deformed. Could that be true?

You may be referring to the photo from the too-tight bushing that made too much neck tension, rather than the nearly unmarked bullet stuck in the seating stem. I've already ordered a larger bushing to fix the seating pressure deformation problem, now I'm only concerned with why this seating stem and this bullet are sticking together so badly. Thankfully, switching bullets let me move forward.

 

[Rocketvapor]

OK, thanks for clarifying the distorted bullets.
The sticking can be fixed by determining which bullets will work without modifying the stem.

I have several for my 5.56 and 22 Nosler. Some work well (repeatable) with the Hornady standard stem, some with the AMAX stem and some with a sanded AMAX stem. I have an RCBS and a Reading seating die but like the Hornady and my color coded seating stems

You may end up with one stem for 2 or 3 bullets, another for 2 or 3 other bullets, etc.
Good old lead core bullets are not as easily damaged as the ELD or VLD or RFD bullets.

 

[howe0001]

In the die-hard reloading community, is it "looked down on" if you spin up a new seating stem on a lathe, bore out the cup on the end, fill with JB Weld, place lubed projectile (so it will separate with JB Weld) in the new stem (axially aligned of course) and using that as your seating stem for that particular bullet? is there any reason that would be a bad idea? (and of course, for each other type of bullet: amax, rdf, smk, ncc, etc,etc you make a custom seat for them)

Assumptions: it's all aligned properly.

??

 

[spife7980]

In the die-hard reloading community, is it "looked down on" if you spin up a new seating stem on a lathe, bore out the cup on the end, fill with JB Weld, place lubed projectile (so it will separate with JB Weld) in the new stem (axially aligned of course) and using that as your seating stem for that particular bullet? is there any reason that would be a bad idea? (and of course, for each other type of bullet: amax, rdf, smk, ncc, etc,etc you make a custom seat for them)

Assumptions: it's all aligned properly.

??

Not at all... provided your assumption holds true.

If not then you would have a ruined stem thats now pushing your bullet in crooked.