Checking seating pressure.

Installed the K&M add-on tonight and just did a function test using a 6PPC case literally iaying around. Neck was sized enough to do the check. Indicator read 35 thou at full seat. So that's supposed to be 35 lbs seating force? Used a typical Cen-Tech dial indicator hanging around my bench. It has 1 inch travel which isn't needed. A half inch travel would be plenty. I'll play with that for a bit and if I decide to continue I'll look for a smaller dial with half inch travel. Preliminary look indicates to me that if you get the right feel on the handle of the press you could probably be within no more than a lb or two measurement. Might even be able to get it closer. The electronic indicator I have is mounted on a granite plate right now and I'll take it off to try that next to see how well the "max" function works.
 
The question that I've never found the answer to is in what way bullet release force is related to seating pressure.
 
I think that we are talking about more than one factor here, not just the force to push (or pull) a bullet from the neck of a case in which it has been seated, but also the size of the step behind the heel of the bullet, and what that restriction allows in the way of seating beyond the point where the bullet first touches the rifling. With minimal neck tension, bullets cannot be seated very much longer than "touch" without being pushed into the case as the round is chambered, but as neck tension increases, this distance increases, not just because of the increase in grip of the neck on the bullet, but (I think) also because it becomes increasingly difficult to get past the step, and the more deeply wedged a bullet is in the rifling, when its round is chambered, the more pressure it takes to start in on its way down the bore (conjecture on my part), so with a given charge of powder, the starting pressure will be higher. Some powders, like 133 seem to "like" a higher starting spike, while others do not seem to "need" it as much to do their best work.
 
Boyd, pull pressure for me is a lot less than seating pressure with the bullets i use the the pressure ring is.0005 larger than the shank.It's like putting a expander in the neck,and spring back doesn't close the neck back tight in front of the pressure ring. I could not even check a dummy round it would stick and pull the bullet. I ended up jump them and it shot good but not as good as in…….. jim
 
John Kielly said:
The question that I've never found the answer to is in what way bullet release force is related to seating pressure.
Click to expand...

and that's the real question that needs to be answered. I recall dave dorman showing prototype seating tool to me, my question was the same told him a few variations instead of measuring basically useless information.
 
I agree that annealing a great way to improve the consistency of your neck tension. That and selecting the right size bushing, or having custom cut dies will help immensely.

I saw the K&M mentioned earlier. Have you seen the new hydro bullet seater from 21st Century shooting? I saw this posted on 6mmBR last week and it looks very well made.

 
Two things......


#1, that 21st Century Dude is a thinker. Second of his vids Ryan's led me to today, I'm impressed.

#2, since I've learned to weigh powder I pay less attention to seating pressure :)

al
 
I like the hyd. set up but the gage is not fine enough. I separate them by 2 lb. or .002 on the indicator. I use an old Federal 1/2" travel with a 3" dial and it very accurate. I don't know if you can get a pressure gage in single pound scale. i do like the idea but testing 5 lb. made a huge difference at 1000……. jim
 
Harbor Freight Postal Scale

I set my press and dies on a Harbor Freight postal scale give readings in pounds and oz's
 
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