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New 21st Century Shooting Hydraulic Arbor Press

Steve, You are right on it….. I found with the Dasher 30-32 lbs. of force to seat worked well and i can hold a .0005 seating depth variance. But if you go up or down in seating force it will change your seating depth and most can't be adjusted back so they are fowlers or sighters. The ES. is single digits in this area,but i don't have a clue what works with the big stuff…… jim
 
CBTO is affected by seating forces, especially with 10cal+ secant ogives. But I couldn't imagine anyone not verifying CBTO with each loaded round.
It only takes a few seconds to check em.
 
Mike,
In short range we do most of our measuring at the target, and groups can change when a different sized bushing is used. I understand all of the factors that can effect bullet pull, but for the overall effect in tuning, with flat base bullets (common in short range), there is another. At the base of the seated bullet, there is a step where the as sized diameter meets the larger diameter surrounding the base of the bullet. The size of this step, combines with the friction between the neck and the bullet to become the total resistance that a bullet has to being seated deeper in the case neck. This comes into play when using seating depths near jam (classic benchrest definition) the higher the resistance to the bullet being seated deeper as it is chambered, and the longer that the bullet can be seated without simply moving into the neck without being "soft seated" as it is chambered. The farther that the bullet is seated into the rifling, the harder it is to start down the barrel. This effects the starting pressure and timing to the muzzle, hence tune. Some time back, when I was working on fire forming some Norma PPC brass that came .006 shorter than my chamber's headspace, I found that when I seated less into the rifling that the result was that the case was not formed to the "headspace" that it had been with the same powder charge, because that slight adjustment lowered the starting pressure. Adding a little more powder put me back where I wanted to be. BT bullets are a different matter.In short range, we play a slightly different game, by different rules than the long range crowd, which is why I pay close attention when someone from another discipline speaks about how it is done for his game. In ours, the common use of arbor presses to seat bullets gives shooters rather direct information on the effects of various factors on the amount of effort that it takes to seat a given bullet, and to the extent that one of the things that we are dealing with is how much force it takes to seat a bullet deeper as a round is chambered, this useful information, not the same as bullet pull, but nonetheless useful.
 
In part I was interested in the 21 century solution as some bullets seat deeper despite sorting and having a more noticeable increase in pressure to seat. I am curious to see if seating pressure correlates with precision of seating depth.

Does sorted bullets plus consistent seating pressure but inconsistent seating depth equal a variable that's not understood in my reloading process. (rhetorical)
 
I believe that one factor in what you have described is the width of the contact between the seater stem and the bullet, and where on the bullet it is. Also, different seating equipment and setups have different potential for depth variance caused by differences in the force required for seating bullets. I would expect that an arbor press setup with the broadest possible contact with the bullet would give the least variation. A friend who has two different brands of sliding sleeve threaded seaters prefers one over the other due to a difference in their ogive to head uniformity.
 
BoydAllen said:
I believe that one factor in what you have described is the width of the contact between the seater stem and the bullet, and where on the bullet it is. Also, different seating equipment and setups have different potential for depth variance caused by differences in the force required for seating bullets. I would expect that an arbor press setup with the broadest possible contact with the bullet would give the least variation. A friend who has two different brands of sliding sleeve threaded seaters prefers one over the other due to a difference in their ogive to head uniformity.

Boyd:
Being a group shooter, I have recently become more aware than ever in regards to "seating stems" . Since examining a custom seater at last years Super Shoot, in relation to the stem making contact with the bullet, , I believe I will stop using the Wilson seater. I have three stems for the Wilson and and not at all happy with any.
For one thing, ( in my mind) base to ogive must be exact for each bullet you seat, and that can only be accomplished by ( 1) measuring each one with a comparator using a digital readout, and ( 2 ) having a seating stem which bears on the ogive of that particular bullet. The one demonstrated to me left a mark completely around my bullets at that point. To me, it doesn't get any better than that.
I'd like to name the person who machines these but won't unless someone asks.
 
Consider yourself asked. I will disagree with you about one thing. It is not the distance from the base of the bullet to the ogive that matters, but the consistency of the distance from where the stem contacts to where the rifling will contact that is the real issue. All other things being equal, differences in the distance between these two contact points will show up directly as variations in seating depth relative to the rifling.
 
BoydAllen said:
Consider yourself asked. I will disagree with you about one thing. It is not the distance from the base of the bullet to the ogive that matters, but the consistency of the distance from where the stem contacts to where the rifling will contact that is the real issue. All other things being equal, differences in the distance between these two contact points will show up directly as variations in seating depth relative to the rifling.

Boyd;
The man is Don Nielsen, aka "The Pumpkin". Same guy that makes the (Orange) round neck turner.

Yes, Actually that is true. However, to my thinking, if the numbers read the same on your bullets with a comparator using a digital, at least you know that when you find your seating depth, they will all be the same. I may not be putting this in the proper wording, but you know enough to understand what I mean. And...thanks for asking.
 
JamesnTN said:
Make that 2 of us asking. I'd be interested in custom made seater stems.

James;
It's not only the stem, but the whole seater. Don is the VP of
NBRSA in Winnetka, CA.
818-883-5866
pkin@sbcglobal.com
 
Bob Greens comparator measure from where the stem touches the bullet to where the bullet contacts the rifling . My seating depth is finally accurate to within.001! Hooray.
 
jam711 said:
Yes, Actually that is true. However, to my thinking, if the numbers read the same on your bullets with a comparator using a digital, at least you know that when you find your seating depth, they will all be the same. I may not be putting this in the proper wording, but you know enough to understand what I mean. And...thanks for asking.
[br]
No, that is not correct and Boyd had it right. The only way to ensure consistent seating depth is to measure bullets from seater stem contact to rifling leade contact. That is what Bob Green's comparator does. Measuring base to ogive tells nothing about what is forward of the comparator contact. Most of the Berger Hyrbrids I use fall into a .003" range, as measured with Bob's tool. But, ~5-15%, lot dependent, are outside that range, sometimes way outside. You don't want that much variation in seating depth, relative to rifling leade. My seating depth is as JVON's, within .001" of nominal.
 
Steve;
You boys are correct in what you say. I should have stated that with Nielsen seater, Your bullets will be seated straight in the case neck. My apologies for not pointing out my real meaning about this.
 
I have the press and live mine, defiantly give you a real look at seating pressure. As far as comparator O am using Bob Greens it measures from where stem contacts ogive to where bullet contacts lands. Don't know all the tech. But for the 1st time I am getting seating depths consistent to .001. Any questions call Bob Green maybe Erik Cortina can also answer. Thanks a bunch Erik!!
 
JVON said:
I have the press and live mine, defiantly give you a real look at seating pressure. As far as comparator O am using Bob Greens it measures from where stem contacts ogive to where bullet contacts lands. Don't know all the tech. But for the 1st time I am getting seating depths consistent to .001. Any questions call Bob Green maybe Erik Cortina can also answer. Thanks a bunch Erik!!

You're welcome! It took you a while for it to sink in, but I'm glad it finally did! ;)
 
Bob's tool does NOT contact where your lands contact, as land contact depends on YOUR leade angle-vs-YOUR ogive radius. His tool does not contact where YOUR seater stem does either. They are all a bit different.

Bob's comparator provides relative indication of ogive radius change, from bullet to bullet in a lot. It's a comparator.
While this qualifies ogive datums(which is very useful), it still does not set them, and you can still screw up seating with variances in seating force, or bad seater stem contact, or bad measurement methods.

But nobody even needs to know their actual seated distance to/into lands, and by far most don't. All that matters is that you find the seating depth that works best and reproduce it consistently. It can be completely relative to your local tool(dimensionless), and as long as you can reproduce it, you're fine.

Also, if you have rational and consistent seating force, and didn't mung up your seater stem with crazy ideas about where & how it should contact, you can seat every bullet to the same contact distance regardless of your measure, even if ogives vary in radius. If you qualify your ogive datums with a BGC then you can also measure this as consistent.
Under these good/normal conditions, worse case error in seated distance to lands is +/- a thou. With any effort in it you can get below 1thou total variance.
 
On the Nielson seater, I have one that is all that I use for my 6PPC. When it comes to getting the straightest bullet seating, of course you need straight brass, because as seater cannot make up for that, but it can keep what you have so to speak, by fitting the case as closely as possible. The seater that I use has a .262 neck, like my rifle's chamber. and the fit in the body of the case is good as well. It cost me considerably more than a Wilson, but I consider it a good investment. It is a very simple design, without any sort of micrometer, and that is how I like it. I find that I like the directness of changing the total length of the stem and cap, as measured with my calipers. That is the dimension that I record in my load notes, as well as the approximate relation to the rifling. I have compared the results that I have gotten with different seaters, which is why I use his.
 

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