Hornady OAL gauge-Did I miss something?

[joshb]

I'm trying some new .223 bullets and I'm using the gauge in my gun. I'm writing down my measurements to ogive ( usually 20 for an average) and I found myself staring at the Hornady case. I suddenly think I've been doing it wrong. I size my "good" cases using the Boyer method. Remove firing pin and push back shoulder for slight resistance on bolt close. The Hornady case is not formed for my chamber or zero headspace in my gun. Are my measurements to ogive therefor inaccurate? Seems to me they would have to be off.

 

[dkhunt14]

If the case is shorter in headspace then the case you use, it could be off some. I wouldn't think it would be more then a few thousandths. Look at Alex Wheelers video on seating depth. I think it is probably the most accurate and repeatable way. Matt

 

[Ned Ludd]

For the reasons you mentioned the Hornady OAL gauge (Stoney Point tool) will not necessarily give you an "exact" measurement, but rather a "relative" value. However, it is a very easy and useful tool for obtaining a starting point for seating depth in load development, as well as routine measurement of land erosion. As long as you're aware it may differ from the "true" value by as much as 2-3 thousandths, it doesn't matter. Ultimately, you will be seating, measuring, and firing actual rounds. The measurements and precision results you obtain from those are not relative and will define the optimized load parameters. Because of the relative nature of the Hornady OAL gauge measurement, I typically don't try to move the seating depth any closer to the lands than about 5-6 thousandths, unless I'm purposely trying to seat bullets into the lands. The measurements may be off by a couple thousandths, but not that much.

 

['Freak]

Drill & tap your own “special case” that you know (been checked using a stripped bolt) is blown out to fit your chamber’s bolt face to shoulder datum dimension with zero or right at zero headspace.

That, or you could switch to using Sinclair’s “Bullet Seating Depth Tool” instead. where you can use, and in a separate step from checkin’ the bullet, any case you please but preferably it’ll be one that’s been blown out as described above.

 

[K22]

Use the Franklin arsenal tool, it's cheap, simple to use and accurate. Or you can make one using nylon spacers, tapping them and installing nylon threaded screws available at Home Depot. See Midway catalog for illustration of the Franklin tool. The tool works for all calibers. I know of one major custom rifle maker who uses this tool for his reloads.

 

[K22]

On ogive - The varmint bullets I use namely Nosler and Hornady ogives can vary anywhere from .001 to .004" from bullet to bullet, some lots are more consistent than others. I set my OAL to account for the max variation because I do not want my reloads any where near the lands. I typically set at .010 to .020" from the lands depending on the rifle. This works very well for me, groups in the 1/4 moa range are normal for my custom barreled varmint rifles.

 

[mikehotel]

Interesting... I discovered today... that the (my) Hornady O.A.L. tool isn't that accurate....

I ended up loading up a dummy round long, and kept resizing until the bolt (firing pin removed) would close easily. The new measurement was .008 longer then anything I could get the tool to do.

Measured both c.o.a.l. and ogive. BTW this was on a 6.5CM RPR.

 

[Dusty Stevens]

Use one of your cases and your bullets. You dont need a tool.

 

[Brians356]

I have made my own modified cases (using once-fired) for my Stoney Point (Hornady) tool. I became curious recently and measured my modified 223 Rem case against the Hornady-supplied 223 Rem case (using the Hornady .330" comparator, i.e. datum on the shoulders) and was surprised to discover they both have exactly the same lengths to the shoulders. Even if you make your own cases, unless you take pains to size every subsequent case to the same shoulder length as the modified case, you can introduce the same type of error. As "gstaylorg" points out, it's not an absolute measurement so much as a baseline for reference, i.e. a somewhat arbitrary stake in the ground.
-

 

[dickn52]

I thought you could send a case to Hornady and they would make it and return it for you? I thought I read that somewhere. Just read the manual, and the second to last page is dedicated to sending YOUR fire formed brass to them for their modification and return.

 

[Brians356]

I thought you could send a case to Hornady and they would make it and return it for you? I thought I read that somewhere. Just read the manual, and the second to last page is dedicated to sending YOUR fire formed brass to them for their modification and return.

Yes, Hornady will. But you can also just drill and tap the same case yourself. The result will be exactly the same, but you will have it in an hour rather than days or weeks (I don't know how long their turn-around is, or what they charge.)
-

 

[fguffey]

Reloaders insist on tapping/threading the primer pocket/flash hole; that was never necessary. A reloader can drill the flash hole/primer pocket on a fired case to maintain the length of the chamber from the shoulder of the chamber to the bolt face; and then neck size the case. After removing the bolt chamber the test round, after chambering the round use a cleaning rod to push the bullet out of the case and into the lands. When the bullet hits the lands stop pushing then remove the test round.

I want all the bullet hold I can get.

I use the test round as a transfer, I transfer the dimensions of the chamber to the seating die. I want to know the length of the chamber from the rifling to the bolt face. I understand most feel comfortable when they are surrounded by tools. I do not believe all of those tools are necessary and they can not be simple. If they were simple reloaders would not require counseling, therapy and support.


F. Guffey

 

[Brians356]

I do not believe all of those tools are necessary and they can not be simple. If they were simple reloaders would not require counseling, therapy and support.

But, without tools, life is not worth living. At least not for a man.

Suppose someone is already unfortunate enough (notwithstanding your admonitions) to own a certain tool such as the Hornady (nee Stoney Point). Should he not use it? Shall he let it languish in a drawer lest he be considered a fool for possessing it, and in need of therapy if he seeks advice on its application?
-

 

[Zero333]

Interesting... I discovered today... that the (my) Hornady O.A.L. tool isn't that accurate....

I ended up loading up a dummy round long, and kept resizing until the bolt (firing pin removed) would close easily. The new measurement was .008 longer then anything I could get the tool to do.

Measured both c.o.a.l. and ogive. BTW this was on a 6.5CM RPR.

Subtract the headspace length of your chamber from that 0.008" because the Hornady modified case measure the same as a go-gauge for that cartridge. So if your 6.5cm RPR headspace is 0.0035", your 0.008" difference in methods is really 0.0045"

 

[fguffey]

Interesting... I discovered today... that the (my) Hornady O.A.L. tool isn't that accurate....

Discovered today; If it was accurate the measurements would match SAAMI specifications or measurements furnished by R. Lee in his book on modern reloading. I reloader could verify a gage, any gage, the reloader that owns a gage they thought was a head space gage but is a comparator or case gage could verify the comparator or a case gage.

The problem with a Hornady/Sinclair is the datum? It has a radius; the radius is as misunderstood around reloading forums as the datum. I make datums, my datums are not case friendly because my datums do not have radiuses. L.E. Wilson case gages use a datum with a radius.

Then there is the concept of zero.

F. Guffey

 

[Brians356]

fguffey,

I'm sure that all makes perfect sense.

mikehotel,

You cannot get a jammed measurement with the Hornady tool that will duplicate the jammed dummy round. How tight was the neck dripping the bullet? With much grip at all, the camming action of your bolt action is far greater than what you can apply to the bullet with the tool stem and hold while at the same time lock the set screw to record the measurement. Your dummy round is naturally forcing the bullet farther into the lands than the tool. That .008" difference is not surprising at all.
-

 

[ireload2]

I don't why you keep harping on the gage datum when it is not a true functional datum. Yes it gives some what usable results in light duty use and it meet SAAMI drawings for measurement and verification. But in many cases it is not a durable datum suitable for long term heavy duty use.
A true functional manufacturing datum would not be the edge of a hole, it would be a basic cone that the entire case shoulder fits against just exactly like it has to fit against the shoulder of the chamber. After all, the entire shoulder of the cartridge has the potential of hitting the chamber at any or all parts of the shoulder depending on deviations from the basic angle and surface texture or profile defects.
As proof of this you will notice that gunsmith headspace gauges for manufacturing the chamber actually have a full size conical surface to engage the shoulder of the chamber. No gun manufacturing company would use a gauge with a sharp edge to set the headspace dimension of a chamber.

Reloaders insist on tapping/threading the primer pocket/flash hole; that was never necessary. A reloader can drill the flash hole/primer pocket on a fired case to maintain the length of the chamber from the shoulder of the chamber to the bolt face; and then neck size the case. After removing the bolt chamber the test round, after chambering the round use a cleaning rod to push the bullet out of the case and into the lands. When the bullet hits the lands stop pushing then remove the test round.

I want all the bullet hold I can get.

I use the test round as a transfer, I transfer the dimensions of the chamber to the seating die. I want to know the length of the chamber from the rifling to the bolt face. I understand most feel comfortable when they are surrounded by tools. I do not believe all of those tools are necessary and they can not be simple. If they were simple reloaders would not require counseling, therapy and support.


F. Guffey

 

[fguffey]

I don't why you keep harping on the gage datum when it is not a true functional datum.

I understand; you do not know. And then there is that other part; if another member understood they would correct your response. No one remembers back when all the information available about the datum was a one dimensional drawing with a line drawn through the shoulder with an arrow identifying it as ‘the datum line’. With the drawing the poster of the drawing would add the phrase; ‘And that is how they do it’.

Some reloading forums still use the drawing; few if any understand what it means or how it is used. As sure as I am they do not know how it is used I am equally convinced they do not know how to ask.

F. Guffey

 

[joshb]

Well, I got what I wanted! A conversation. Some comments I get, some I'll have to read again. Old brain syndrome. I looked back thru the archives and read a few posts that had some info but nothing that clear. I'll admit that I had watched the Wheeler video a while ago. It was prolly habit that kept me using the Hornady tool but I guess the video planted a seed in my brain to question my method. Thanks for every ones input. Any one else have an offering, I'd like to here it. I'm definitely changing my method.

 

[waldo1979]

Ditched the Stoney point / Hornady tool and never looked back. I much prefer the Sinclair tool where I use my own sized brass.