Neck Tension Too High?

MCHOG

Gunny Sergeant
Full Member
Minuteman
Dec 6, 2018
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Atlanta, Georgia
I had to use my kinetic bullet puller for the first time recently. To get the bullets unseated, I had to beat the ever living shit out of it (probably 10+ HARD hits on plywood clamped to my work bench). I really can't believe the plastic survived the 8 or so rounds I had to pull. I've seen videos of folks unseating bullets with a single authoritative hit. Is that evidence that my neck tension too high?

The info:
6.5 mm 147 ELDM
Hornady once-fired 6.5 CM brass
No anealing
Sized with Forstner full length sizing die using Imperial wax
Neck tension set with Sinclar .263 carbide expander mandrel without lube
After using the mandrel, inside case diameter measures .2610 with a Mitutoyo caliper
Forster Co-Ax press
Puller is a Frankford Arsenal Quck-N-EZ

The mandrel is new and my groups have opened up a little recently. Not sure if this is the cause.
 
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I would say so. Non annealed brass will have more tension than annealed at the same measurement. Imho, .003 is a bit much anyways.

I recently went down the case neck tension rabbit hole and bought some individual plug guages to accurately measure inside diameter. Surprising how off cases can be even after a mandrel. Some require multiple times through it. After that my es and sd dropped to the lowest its ever been.
 
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I generally have my 6.5 neck ID at .2610 and haven’t had any problems pulling bullets in the past. I use one of those Hornady Cam Lock pullers. I do anneal my brass but I don’t think it would make that much difference when pulling bullets.
 
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I had to use my kinetic bullet puller for the first time recently. To get the bullets unseated, I had to beat the ever living shit out of it (probably 10+ HARD hits on plywood clamped to my work bench). I really can't believe the plastic survived the 8 or so rounds I had to pull. I've seen videos of folks unseating bullets with a single authoritative hit. Is that evidence that my neck tension too high?

The info:
6.5 mm 147 ELDM
Hornady once-fired brass
No anealing
Sized with Forstner full length sizing die using Imperial wax
Neck tension set with Sinclar .263 carbide expander mandrel without lube
After using the mandrel, inside case diameter measures .2610 with a Mitutoyo caliper
Forster Co-Ax press
Puller is a Frankford Arsenal Quck-N-EZ

The mandrel is new and my groups have opened up a little recently. Not sure if this is the cause.

I have the kinetic bullet puller you mention, but don't use it any more since I got a Hornady puller. I never really had as much of a problem with the kinetic puller that you're having. Neck tension could certainly be a big factor as does cases that have not been annealed and more so each time they are fired as the harness increases so does the grip on the bullet with the same neck tension. Another factor could be lack of any lube on the inside of the neck, which would add to the amount of grip the neck has on the bullet. A super clean neck interior without any lube will result in a lot of grip on the bullet and this is why many reloaders don't clean the inside of their cases.

When you measure neck tension, you should be measuring the outside of the neck, not the inside. To find out your neck tension, measure (on the outside) the neck of a case that you've finished preping and measure the neck of a case with a seated bullet. The difference is your neck tension.

Trying to measure the inside diameter with a caliper (even a Mitutoyo) is much more difficult in getting an accurate measurement. The numbers you're showing there don't seem to add up . . .???
 
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The plywood may have actually cushioned the hammer blows. Next time try it on a concrete slab which will result in a sharper blow and dislodge the bullets sooner.

Collet pullers work a lot easier.

Yep. Like he said it does matter what you bang on. I use the end grain of a 4x4. I just can't bring myself to bang a plastic tool on concrete.
 
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The puller instructions said to only do it on wood. I started it on my work bench top, but started denting it so I turned to the plywood. Maybe I'll use a 2x4 next time.

The bullets had only been seated for a few minutes, so I don't think the welding was an issue. I should have included in the original post that when I use the mandrel, I let it sit in the case for a second or two to reduce spring-back. I guess that didn't help.

I'm doing some loading tonight, so I'll measure the difference in outside diameter and use some Imperial dry neck lube. I'll seat one just to pull and see what happens.

I will certainly anneal after this second firing.

The only reason I didn't go with a collet puller is because I heard it marred the bullet. But I ended up bending the tips of about half the bullets anyway, even after I replaced the factory foam in the puller with a foam ear plug.
 
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The puller instructions said to only do it on wood. I started it on my work bench top, but started denting it so I turned to the plywood. Maybe I'll use a 2x4 next time.

If you're going to use a 2x4, make sure it's made of hard wood and not soft like fir. I've always used mine on concrete, though I made sure my blows were not too hard, but just enough to dislodge the bullet within 2 blows. I found the kinetic puller was fine for just a couple, but when I had several the collet puller is just a much better way to go.

The bullets had only been seated for a few minutes, so I don't think the welding was an issue. I should have included in the original post that when I use the mandrel, I let it sit in the case for a second or two to reduce spring-back. I guess that didn't help.

Having a somewhat long dwell time like that DOES help in reducing spring back. But, the harder the brass becomes, the longer dwell time it takes and even then, there's only so much you can do when the brass is not annealed.

I'm doing some loading tonight, so I'll measure the difference in outside diameter and use some Imperial dry neck lube. I'll seat one just to pull and see what happens.

(y) (y)

I will certainly anneal after this second firing.
👌

The only reason I didn't go with a collet puller is because I heard the marred the bullet. But I ended up bending the tips of about half the bullets anyway, even after I replaced the factory foam in the puller with a foam ear plug.

I've never marred any bullets with my Hornady collet puller, though I make sure I'm not clamping down unnecessarily hard to pull them. I've not even had any marring on the part that's seated in the neck and but reused bullets performed just as well as those that had never been seated before. What it really nice to is that I don't have any powder flying around like I often did with the kinetic puller. :eek: ;)
 
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When I use a kinetic puller I strike a wooden mallet held in my hand, works good and is quiet. With the 147's you are probably into the neck
shoulder junction and that area is not easily stretched as the rest of the neck by the bullet. possibly adding to the grip.
 
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I had to use my kinetic bullet puller for the first time recently. To get the bullets unseated, I had to beat the ever living shit out of it (probably 10+ HARD hits on plywood clamped to my work bench). I really can't believe the plastic survived the 8 or so rounds I had to pull. I've seen videos of folks unseating bullets with a single authoritative hit. Is that evidence that my neck tension too high?

The info:
6.5 mm 147 ELDM
Hornady once-fired 6.5 CM brass
No anealing
Sized with Forstner full length sizing die using Imperial wax
Neck tension set with Sinclar .263 carbide expander mandrel without lube
After using the mandrel, inside case diameter measures .2610 with a Mitutoyo caliper
Forster Co-Ax press
Puller is a Frankford Arsenal Quck-N-EZ

The mandrel is new and my groups have opened up a little recently. Not sure if this is the cause.

If your calipers are saying 3 thou neck tension, its probably more like 2 thou. My Starline brass sprung back about a half thou when it was virgin and a bout a full thou at 1x fired, no annealing. So I used my expander mandrel and that got me about 2-2.5 thou neck tension. All of this was checked with Class ZZ pin gauges(+)

3 thou neck tension is not necessarily too much. If 3 thou is too much, and 1 thou isn't enough...then that leaves only 2 thou as the right answer? Nahhh

I would review your whole reloading process and see if something else is happening. When you say the mandrel is new...did you introduce it when you started reloading the 1x fired or in the middle of the process and its suffering now?

You could walk us through your exact process step by step and maybe someone can spot where another change/shift may have caused a change in accuracy
 
I’d order some .001, .002 under pin gauges from amazon. They are cheap and easier to use to check neck tension. And unless you’re really hitting the ammo in some hard that match move the bullet, .001 and .002 tension is plenty.