Question for hornady fans.

Z

zanemoseley

New member
I'm looking at getting a few hornady items, the OAL gauge, bullet comparator basic set and the headspace gauges with comparator.

I see they sell the headspace gauges with and without the comparator. Is it the same comparator as the one that comes with the bullet comparator set. No need for two of they're the same ones right?
 
If what they call the comparator is the red part that attaches to your calipers, then no you don't need two of them. The headspace gauge set and the bullet comparator set use the same red piece that attaches to your caliper. I have all three of those tools so if my answer isn't clear enough let me know.
 
It is but the two pictures look slightly different but I can't tell if it's just the angle of the photo. I was hoping someone could confirm if they're the same or not.
 
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They are case comparator inserts for the Hornady caliper insert adapter. The Sinclair adapter accepts them as well. The only difference between the two adapters is the Hornady is offset from center slightly to line up bullet comparator inserts with the Hornady OAL gauge, while the Sinclair is centered for easier comparing when a case head is directly on the caliper anvil.

The reason for making the distinction from a headspace gauge is an actual headspace gauge, like the ones shown below, is needed if you intend to make an absolute measurement with the case inserts rather than just a comparison. The inserts have a slight radius at their case shoulder datum diameter holes, so if you simply close the caliper jaws to pinch the insert against the anvil and zero the readout, then the reading you take off the case will be a little short. Folks have reported 0.002" to 0.009" short, that I recall. Mine are usually short around 0.004" for 308. It will vary with the shoulder angle and how much radius was bead blasted into the particular insert. This varies a bit. So, for an absolute measurement, you need to zero the comparator on a ground steel headspace gauge of known value.

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You guys are getting over my head in a hurry. Regarding the headspace inserts I watched a YouTube video where a guy showed that there was .008 difference if I remember between the OAL brass and actual brass, can't remember if it was sized brass or brass fire formed in the chamber.

Whether or not it's worth messing with may be up for debate. I guess a lot matters on how close you want to ride off the lands. Of you're just shooting for .030" off the lands it may not matter, if you're going for .005 then it may even mean you're jammed into the lands.
 
Hey Zanemoseley, the tools work fine for what you are trying to do. The OAL gauge and bullet comparator work fine to determing how far off the lands you are and to check your seating depth. The case headspace comparator works fine to check how far you are pushing your shoulders back when sizing. That's all I have ever used them for.
 
The reason for making the distinction from a headspace gauge is an actual headspace gauge, like the ones shown below, is needed if you intend to make an absolute measurement with the case inserts rather than just a comparison. The inserts have a slight radius at their case shoulder datum diameter holes, so if you simply zero by closing the jaws, then the reading you take off the case will be a little short. Folks have reported 0.002" to 0.009" short, that I recall. Mine are usually short around 0.004" for 308. It will vary with the shoulder angle and how much radius was bead blasted into the particular insert. This varies a bit. So, for an absolute measurement, you need to zero the comparator on a ground steel headspace gauge of known value.
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I make datums, I make datums that are not case friendly, my datums do not have radius. When a reloader realizes he can zero off of a sharp datum he will realizes he does not need a head space gage/transfer/standard. I doubt the sun will get brighter or music will began to play. Anyhow I always hold out hope.

F. Guffey
 
I do too, particularly in regards to terminology that makes no sense.

If you are going to be obscure, at least cite a reference we can look at so we can determine the validity or lack there of.
 
I do too, particularly in regards to terminology that makes no sense

If you are going to be obscure, at least cite a reference we can look at so we can determine the validity or lack there of.
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I do too? You do to what?

What part of zero do you not understand? What is there about a standard do you not understand? If you do not understand the function of a datum; ask someone that does.

F. Guffey
 
The case headspace comparator works fine to check how far you are pushing your shoulders back when sizing
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If you are going to be obscure, at least cite a reference we can look at so we can determine the validity or lack there of.
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You have two standards; the first quote claims the case has head space. In the same sentence there is a claim the shoulder is pushed back.

RC20, you want to show off? Jump out into the fast lane.

F. Guffey
 
Hornady sells both a cartridge headspace set and a bullet comparator set.

As Unclenick mentioned when measuring cartridge headspace from a fired case with the Hornady set I come out at 1.638" compared with 1.631" using a Forster match rifle headspace gauge set. This is why I use the Hornady set as a comparator to simply compare how far I push the shoulder back.



Unlike Guffey some of us are not able to make our own datums, transfers, and standards so we need to use tools made for the common man.
 
Unclenick says:

"The reason for making the distinction from a headspace gauge is an actual headspace gauge, like the ones shown below, is needed if you intend to make an absolute measurement with the case inserts rather than just a comparison. The inserts have a slight radius at their case shoulder datum diameter holes, so if you simply zero by closing the jaws, then the reading you take off the case will be a little short. Folks have reported 0.002" to 0.009" short, that I recall. Mine are usually short around 0.004" for 308. It will vary with the shoulder angle and how much radius was bead blasted into the particular insert. This varies a bit. So, for an absolute measurement, you need to zero the comparator on a ground steel headspace gauge of known value."

Absolutely true. My Hornady Headspace gauges have very poor reference datum and they are brand new. The factory took a crude deburring tool and put a chamfer on the inside of the hole. Dumb. Hopefully you can view this photo - (looks like in Preview mode you'll have to click on a link instead of having it just show up below this text - sorry if that's so - I'll try to figure out photos later)

This is my C375 from the set with a .009" shim laying on top for reference. You can see that the chamfer is deeper than the shim, and that there are scratches in the chamfer, which will cause more inaccuracies. I should have just made my own from scratch! I am going to take these to my shop and machine off the top so that I have a perfect .375" diameter hole with a crisp edge to measure from. I'm going to complain to Hornady also.
 

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Unlike Guffey some of us are not able to make our own datums, transfers, and standards so we need to use tools made for the common man.
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Again, forgive. Many years ago I started out to convince reladers it had nothing to do with making tools, it is all about understanding the tools you are using.

I purchased a mill from a builder of period correct military rifles; he is also a reloader, shooter and collector. He was on a reloading forum that was so dysfunctional it disappeared, and then; it reappeared after they dumped the archives.

He was trying to check the head space, being a perfectionist he did not accept the fact he did not know the length of the chamber. He had no fewer than 20 plus head space gages. Not one of the gages would indicate the length of the chamber. I suggested he visit the shop of a common friend. I informed him there was an old head space gage that measured head space in thousands, our friend has one. Then I offered to modify his head space gages to measure the length of the chamber from go-gage to infinity. I offered to take tools off of his wall and out of his tool boxes or from his work bench to check the length of the chamber.

He said he had a new box of R-P 30/06 ammo he was going to use when test firing. I thought that was a brilliant ideal so I checked his rifle. The difference in length between his new ammo and the length of the chamber was .0075”. That was for all 20 rounds. We are talking about the length of the case from the shoulder to the case head and the chamber length from the shoulder of the chamber to the bolt face.

Again, he has no fewer than 100 03 and 03A3 bolts, I have no fewer than 30, between us we did not have a bolt that would correct the length of the chamber by .0025”. The search was made more complicated because the rifle was period correct for a Rock Island 1911 03. The rifle has a straight handle bolt. I have one that is in a Rock Island 03 and he had the one with a chamber that was between a go-gage and no go-gage length.

F. Guffey
 
k2man said:
I am going to take these to my shop and machine off the top so that I have a perfect .375" diameter hole with a crisp edge to measure from.
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I did that with my .400 insert in hopes of getting an absolute case headspace measurement on .308 Win cases. It didn't happen. I do get a different reading than before the mod, but it's still just a comparator, no more, no less.
 
higgite, why would you not get a good absolute measurement after milling the chamfer out of the gauge? If the hole is round and the right size, and the bullets are round, seems like it would be the way to properly measure a cartridge.
 
Bullets are round,
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Then there is the taper: problem; the bullet is not perfect. When using absolute tools on stuff that is not perfect the reloaders gets variations and then it runs into tolerances and not long after that comes the excuses why it can not be done.

F. Guffey
 
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