More interesting information for reloaders.

J E Custom

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An interesting test for bullet seating. It does show the difference in some parameters. I doubt many can afford this equipment, But it is nice to see what effects different procedures have on bullet seating.
I wish they would have included more parameters so we could get a good idea of the best case scenario, Like clean and/or with graphite or Molly coating the inside of the necks.

The change when seating depth was also interesting.


J E CUSTOM
 

venatic

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May 7, 2011
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Appreciate the post very interesting indeed. I now want to try brushing inside of necks on some known rounds to see if ES goes down.
Wonder if tumbling accomplishes same thing?
 

nksmfamjp

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Jan 5, 2004
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What did I learn there....brushing lowers force to seat? What did I learn about accuracy?
 

Mikecr

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NC, oceanfront
There are a lot of things you can see with seating force measure & it can be pretty useful.
An important thing to remember though is that seating force/friction DOES NOT directly represent neck tension (springback grip of bullet).
Also that you need to establish tension in stable form during load development, and manage that exactly.
Where you've well normalized seating friction(high or low), then seating force is more directly indicative of tension (in a comparative sense).

I can point out an issue with their automated seating device: it changes speed with force.
There is static and dynamic friction. To get good measure you have to seat close as possible to the same RATE, as a faster seating rate will read higher than a slower rate.
There must be some force absorption to their device. Possibly the clutch.. And that is slowing the seating rate at higher seating forces, which is bad for comparative measure.

Also, a better approach to comparing of seating forces is to do so in a way that allows adjustment and remeasure until matching. Instead of reading bullet seating force, it's better to measure a 'pre-seating' force with an instrumented mandrel. Then seat bullets when all necks match.
How do you match tension?
With neck sizing LENGTH (not interference).
 
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J E Custom

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I think the main message of the Video is to do the same thing/prep every time to get consistency.
In other words, if you start with clean annealed cases every time the seating pressure should be very consistent. If you apply anything to the inside of the case neck, you should do it every time.

I don't deal with carbon he uses a brush to remove because I clean the cases each time (Inside and out). But if you do, again do it every time.

As usual, (I always want more information) I would have liked to see the difference in the same process with at least 5 cases of the same, prep/procedure to better evaluate which was most consistent, then compare the accuracy with the different process.

It was however, interesting and informative.

J E CUSTOM
 

ntsqd

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Nov 16, 2015
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Upper SoKA
Very informative. It opens up new ideas to explore, for sure. I've been pondering the need for the force gauge on an arbor press. Now I see clearly why I want it.

"Stiction" is what we call Static Friction around these parts.

Does the motor change speed with changing resistance, or are we simply hearing the change in load on the motor? It's a pretty fine distinction because the motor is reacting to the change in resistance and once it does the region where speed is maintained is pretty narrow. I believe that we are seeing some of both, which is probably worse.

Repeating the test with a much stronger motor and over-laying the graphs would be illuminating. I'm guessing it was the classic Engineer's mistake of being too conservative. The lesson my work has taught me is that it is easier to scale back the available force than it is to try to increase it. That is to say (as one of my mentors is fond of saying) "it is easier to hit something lightly with a big hammer than it is to hit something hard with a small hammer". The motor chosen had too small of a margin over the predicted max effort needed.
 

LVJ76

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Feb 2, 2019
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1,355
Location
Tucson, Arizona
An interesting test for bullet seating. It does show the difference in some parameters. I doubt many can afford this equipment, But it is nice to see what effects different procedures have on bullet seating.
I wish they would have included more parameters so we could get a good idea of the best case scenario, Like clean and/or with graphite or Molly coating the inside of the necks.

The change when seating depth was also interesting.


J E CUSTOM
Thanks for sharing J E. Stay safe Sir
 

Gibbshooter43

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Feb 2, 2016
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Cottonwood Creek @ Myrtle, Idaho
Jerry, your posts are always appreciated because they’re tho’t out and informative for guys like me who’ve shot and reloaded for years, but are always looking for areas of improvement. Thanks
 

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