Forster Micrometer seating die question
- Thread starter thefitter
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Re: Forster Micrometer seating die question
Is the drift your seeing ogive variation? Are you sorting your bullets by ogive length?
madd0c
Is the drift your seeing ogive variation? Are you sorting your bullets by ogive length?
madd0c
Re: Forster Micrometer seating die question
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: madd0c</div><div class="ubbcode-body">Is the drift your seeing ogive variation?
<span style="color: #3366FF">Yes I'm measuring at the ogive after seating.</span>
Are you sorting your bullets by ogive length?
<span style="color: #3366FF">No</span>
madd0c </div></div>
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: madd0c</div><div class="ubbcode-body">Is the drift your seeing ogive variation?
<span style="color: #3366FF">Yes I'm measuring at the ogive after seating.</span>
Are you sorting your bullets by ogive length?
<span style="color: #3366FF">No</span>
madd0c </div></div>
Re: Forster Micrometer seating die question
Apparently (other thread) this could also be from the fact that I have no lube inside my neck when seating. I checked my 2 reloading books and saw no mention of lube for seating. That maybe because it's expected that you have some lube inside left over from sizing, I don't know.
Apparently (other thread) this could also be from the fact that I have no lube inside my neck when seating. I checked my 2 reloading books and saw no mention of lube for seating. That maybe because it's expected that you have some lube inside left over from sizing, I don't know.
Re: Forster Micrometer seating die question
If you use neck lube, use graphite or mica.
Also before you think it is drifting, I would highly suggest sorting out about 20 bullets by ogive length and then seating them.
You might see your variance dissapear.
madd0c
If you use neck lube, use graphite or mica.
Also before you think it is drifting, I would highly suggest sorting out about 20 bullets by ogive length and then seating them.
You might see your variance dissapear.
madd0c
Re: Forster Micrometer seating die question
i had the same problem and sorted by ogive and that was it problem solved.
i think longer ogive seats deeper and smaller ones sit higher.. or vise versa i cannot remember.
how ever that is your problem, and i dont use neck lube when i seat them ( but maybe i should )
i had the same problem and sorted by ogive and that was it problem solved.
i think longer ogive seats deeper and smaller ones sit higher.. or vise versa i cannot remember.
how ever that is your problem, and i dont use neck lube when i seat them ( but maybe i should )
Re: Forster Micrometer seating die question
I've also weighed SMK's and compared their weight to their ogive length and found the heavier ones tended to be longer. If you dont have a bullet comparator, you may try weighing them to get closer..
I've also weighed SMK's and compared their weight to their ogive length and found the heavier ones tended to be longer. If you dont have a bullet comparator, you may try weighing them to get closer..
Re: Forster Micrometer seating die question
The concave shape of the seating stem cup is a compromise that does not fit all bullet shapes well.
Someone on this forum has been glassing the cup to fit the bullet.
The concave shape of the seating stem cup is a compromise that does not fit all bullet shapes well.
Someone on this forum has been glassing the cup to fit the bullet.
Re: Forster Micrometer seating die question
Well I'm starting to think it really might be the bullets. I was under the impression that the seating die contacted the same part of the ogive as the comparator. I does not. It contacts much closer to the tip. Therefore any deviation between that spot and the ogive will give a different measurement.
http://riflemansjournal.blogspot.com/search?q=arbor+press
But even so I still feel that there might be some travel in the die. When you turn the micrometer knob the tension does not feel uniform and it even feels like there is a little spring back.
Well I'm starting to think it really might be the bullets. I was under the impression that the seating die contacted the same part of the ogive as the comparator. I does not. It contacts much closer to the tip. Therefore any deviation between that spot and the ogive will give a different measurement.
http://riflemansjournal.blogspot.com/search?q=arbor+press
But even so I still feel that there might be some travel in the die. When you turn the micrometer knob the tension does not feel uniform and it even feels like there is a little spring back.
Re: Forster Micrometer seating die question
'...I still feel that there might be some travel in the die. When you turn the micrometer knob the tension does not feel uniform and it even feels like there is a little spring back.'
There is slack, called "back-lash", in most any threaded device, the costs of making a truly snug fitted screw would be prohibitive. Adjusted correctly, the back-lash won't matter.
The proper way to deal with it is to always approach the adjustment we want from the clockwise direction. If you want to go down a thou, just turn it down. If you want to back up a thou, turn it back ten and then tighten back down nine.
All seating is done between the ram (shell holder) and seating plug in the die, no seater die can reference off the case shoulder.
'...I still feel that there might be some travel in the die. When you turn the micrometer knob the tension does not feel uniform and it even feels like there is a little spring back.'
There is slack, called "back-lash", in most any threaded device, the costs of making a truly snug fitted screw would be prohibitive. Adjusted correctly, the back-lash won't matter.
The proper way to deal with it is to always approach the adjustment we want from the clockwise direction. If you want to go down a thou, just turn it down. If you want to back up a thou, turn it back ten and then tighten back down nine.
All seating is done between the ram (shell holder) and seating plug in the die, no seater die can reference off the case shoulder.
