Bullet Seating Runout

mtJim

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Jan 23, 2022
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Montana
Recently did some barrel break in and load development on a new barrel chambered in 270 Weatherby. Annealed all brass after 3-4 firings, and fully prepped to prepare for loading all to final load from development. Loading Absolute Hammers and didn't notice anything out of the ordinary during load development. However, when seating bullets in latest prepped brass, there is a noticeable stick in the press when raising the press handle from fully lowered position. There is also an audible click as the handle is first raised. There is .008-.010 runout measured on the ogive of the loaded round. The brass itself measures around .002 on the end of the neck near the mouth. A partially seated bullet measures .002 runout and will maintain this all the way until the press handle reaches fully lowered position, where it jumps to .008 - .010 when extracted from the seating die. This is also with two different seating stems - redding seating die. One of the stems is the standard that come in the die, the other is the redding micrometer replacement. Have also tried polishing the standard stem with the bullet and lapping compound, with no improvement.
Is more polishing needed? Any other suggestions?
 

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I'll add that it is Norma brass full length sized with a non bushing die, floating carbide expander button
 
That's definitely seated past the neck-shoulder junction. If there's any sort of donut that could be it. Neck turning may solve that. I'll also add I had similarly bad runout and found that my expander button stem was bent. Pulled it out and went to an expander mandrel, solved it entirely.
 
If you have a new piece of brass try it and see if it does the same. If not then you can abandon thinking there is a problem with dies or press. Resize the new brass the same way you are the old.
 
That's definitely seated past the neck-shoulder junction. If there's any sort of donut that could be it. Neck turning may solve that. I'll also add I had similarly bad runout and found that my expander button stem was bent. Pulled it out and went to an expander mandrel, solved it entirely.
No sign of a donut on any cases I inspected. A 6.5 mm bullet slid through the length of the neck without any hang ups. Nothing on the teslong either. Expander stem looked good, rolled perfect across the table.


If you have a new piece of brass try it and see if it does the same. If not then you can abandon thinking there is a problem with dies or press. Resize the new brass the same way you are the old.
Not a new piece of brass, but one that was fired in the old chamber. Resized it the same, measured .001 runout on the case neck after full length sizing. Seated a bullet and measured .005 on the bullet after seating. Same click and stick of the press handle at the start of the up stroke. If I run a loaded round back into the seating die (set at the same length it was when that round was assembled) I still get the click and stick on the start of the upstroke.

That leads to to think that the full length sizing and case prep is good, the issue is in the seating stem. I'll look into bedding it. That would be better than polishing with lapping compound?
 
You implied that you could seat the bullet in with increments, and these measure low in runout. That you only get a step change in runout with a final seating increment. The seating stem is not doing that.
Donut area comes into play -when you size that donut into play.
I imagine one of the bullet bands is in interference with donut brass at your particular seating depth.

The stick & click part is the stem popping off the ogive (release of wedging) due to mismatch angles and high seating force.
 
You implied that you could seat the bullet in with increments, and these measure low in runout. That you only get a step change in runout with a final seating increment. The seating stem is not doing that.
Donut area comes into play -when you size that donut into play.
I imagine one of the bullet bands is in interference with donut brass at your particular seating depth.

The stick & click part is the stem popping off the ogive (release of wedging) due to mismatch angles and high seating force.
I'm leaning towards this. I wish you had an unfired case to see if it also does it. Only other thing I can think of is the bullet nose is is hitting in the seater and it is not contacting in the ogive allowing it to yaw at the end of the stroke if seating pressure is highest at that point due to compressing powder. Pull your seater plug and see how it contacts on the bullet ogive or of it just contacts the meplat and the bullet can wobble in it.
 
No sign of a donut on any cases I inspected. A 6.5 mm bullet slid through the length of the neck without any hang ups. Nothing on the teslong either. Expander stem looked good, rolled perfect across the table.



Not a new piece of brass, but one that was fired in the old chamber. Resized it the same, measured .001 runout on the case neck after full length sizing. Seated a bullet and measured .005 on the bullet after seating. Same click and stick of the press handle at the start of the up stroke. If I run a loaded round back into the seating die (set at the same length it was when that round was assembled) I still get the click and stick on the start of the upstroke.

That leads to to think that the full length sizing and case prep is good, the issue is in the seating stem. I'll look into bedding it. That would be better than polishing with lapping compound?
I don't know that you'd be able to see a donut well. A set of pin gauges or cutting a case in half would be the only way I'd be sure I didn't have them. If you seat your bullets way long such that the taper of the boat tail is above the NS junction, are you still getting bad runout?
 
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