case gages? EGW vs Dillon

[JagerDog]

0.001" or 0.010"....I'm guessing an interfering radius between the case and the gauge. Both may be "in spec".

[Chocula]

Case Gauge vs Ammo Checker

in truth the EGW is called a chamber checker. Evolution Gun Works #H0616
vs Dillon 223 Head Space/case gage.

my prob is that the EGW allows many finished cartridges to be 'no go'
unless i force fit them.
the Dillon is fine with those same loads.
what am i doing wrong?

[disclaimer; new rifle reloader, old pistol reloader 10 years experience]
much obliged,

Max

I realize this is an older thread, but like many threads concerning case/headspace gauges and ammo checkers, it seems to be missing an explanation for why you were getting different results from each gauge. You should get different results as these are different tools meant for different tasks.

First the EGW Ammo Chamber Checker. This is a chunk of metal that is the same length as the maximum C.O.L. (Cartridge Overall Length) for the specified cartridge. EGW uses a Clymer reamer to cut holes that should match SAAMI minimum chamber size. This is designed to measure finished ammunition. If your ammo fits, it should chamber in ANY gun whose chamber is within spec, assuming proper caliber, etc. It is designed to measure case diameter and max overall length. Just because your ammo does not fit in the gauge does not mean that it won't fit in your gun.

Next the Dillon Head Space Case Gage. This is a chunk of metal that is the same length as the maximum case length for the specified cartridge. The hole is cut larger than that of an ammo checker such as the EGW, so that you can fit fired cases into it. This is designed to assist in die adjustment and in checking if a case needs to be trimmed. You can use a case fired in your gun and to see how much the shoulder gets pushed forward. You can use this to setup your dies to bump the shoulder back either just enough to chamber in your gun (may be longer than spec), or so that a resized case is flush (resized case will be in spec and should fit all guns). You will see a grove cut in the top and bottom of this gauge. With primer side up, this is meant to be held in the air. A case with proper headspace will be longer than the bottom of the groove, but not extend past the non-groove part of the gauge. To check if your case needs to be trimmed, the case is placed in the gauge with the primer side down, then placed on a flat surface. The case should be trimmed so that it falls between the groove and top of the gauge, with the top being the maximum case length allowed by the specification for that cartridge.

Anything that fits in an ammo checker should also fit in a case gauge, but not necessarily the other way around. A case gauge won't tell you if your completed round is too fat or is too long, only what your headspace is relative to spec.

To summarize, an ammo checker is for checking completed ammunition. A case gauge is for setting up your dies and checking trim length.

Chocula

[fguffey]

in truth the EGW is called a chamber checker. Evolution Gun Works #H0616
vs Dillon 223 Head Space/case gage

About the time I did not believe reloading forums could get any sillier, this one got sillier. Chamber checker! And I am surrounded by reloaders that can not check a chamber checker. For years I have made chamber gages, as a reloader I have though nothing of being able to check/verify a chamber gage or a case gage or a Hornady Comparator. And then there is Larry’s digital head space gage.

Larry’s gage is not a head space gage but there is only one reloader that knows that; from the beginning Larry’s claim to having a ‘digital’ head space gage caused reloaders to ooh and aw not knowing Larry was passing off a dial indicator stand as a head space gage, at best it was a comparator but ‘head space was more.

A reloader with a few shop skills should be able to measure the length of a case from the shoulder/datum to the case head in thousandths. A reloader that spends more time reloading than talking about it on the Internet should have the ability to measure the length of a case at least two different ways without a head space gage.

One old smith/reloader was doing all of this before the Internet, he was going ‘it’ in the mid to late 40’s.

F. Guffey

[fguffey]

Next the Dillon Head Space Case Gage. This is a chunk of metal that is the same length as the maximum case length for the specified cartridge.

You forget some silly reloader claimed the case had head space; SAAMI does not list case head space, and then the silly reloader called SAAMI to inform them they made a mistake.

My cases do not have head space because SAAMI does not list case head space; they do list the length of the case from the datum to the case head. When measuring the length of the case I have two lengths. One from the end of the neck to the case head and the other from the datum to the case head.

F. Guffey

[fguffey]

And then there was 1938; L.E. Wilson started selling the 'Wilson case gage' with instructions, I understand that means nothing to the Internet reloader; correction: It means nothing to most reloaders.

In the instructions L.E. Wilson suggested the reloader use a straight edge; Wilson even described the straight edge and suggested the pocket rule would serve as a straight edge. As soon as I read that I added a feeler gage to the straight edge and I used a flat surface because when measuring the length of a case from the datum to the case head I wanted to know the length of the case from the datum to the case head in thousandths.

The Wilson case gage is a datum based tool. Again, I make datums, I can make a datum out of almost anything, if I do not get the correct datum diameter I can use my datum as a comparator.

And that is the reason the Sinclair/Hornady tool is not a head space gage, first the case does not have head space and they could not build an accurate tool that was datum based, so eventually it became know as a comparator.

F. Guffey

[robert101]

I use the Wilson gages and find them very useful. I do use my gun chambers in the process as well.

[ar15barrels]

So what does "force fit" do?

Most often, it knocks down a burr on the case rim which was keeping the cartridge from fitting into the gauge.
This is because most ammo checker gauges are made with chamber reamers and the chamber reamer is smaller in diameter than a boltface.
So some ammo will fail the gauge that fits the gun fine.

I have opened up the rim diameter section of many gauges to make them move useful.

[fguffey]

I use the Wilson gages and find them very useful. I do use my gun chambers in the process as well.

Using the chamber in the process works. A very talented reloader can determine the length of the chamber in thousands if he has a good understanding of the chamber and the effect the case had on offsetting the length of the chamber. BUT? It would appear those that sell gages do not want the reloader finding out all of those gages are nice, nice but not necessary.

F. Guffey

[fguffey]

I use the Wilson gages and find them very useful

Wilson suggested the reloader use a straight edge, the reloaders that understands a flat surface can be used as a straight edge can use the flat surface and a straight edge to determine the length of the case from the datum to the case head.

And then there is the reloaders that understands the Wilson case gage is a datum based tool and designed to measure the length of the case from the datum to the case head and from the datum to the end of the neck.

AND THEN? There are those that never got beyond using the Wilson case gage as a drop in gage. The Wilson case gage was designed to measure a fired cases and a sized case.

And then? When it became necessary to trim the case the Wilson case gage indicated 'by how much'.

Again, this stuff does not lock me up. I have fired cases that are .014" longer than a minimum length/full length sized case that does not require trimming.

F. Guffey

[anyracoon]

I have both. I check first using the EGW. One's that don't fit, I check with a Dillon. Some pass some don't. Also be sure to swab out the inside of the case checkers once in awhile. Had at times stuff get stuck in side of case checkers.

[fguffey]

my prob is that the EGW allows many finished cartridges to be 'no go'
unless i force fit them.
the Dillon is fine with those same loads.
what am i doing wrong?

If you do not read the instructions the instructions could become destructions.

Force fit, I dug out an old Starrett book that dealt with such matters and then I laid the book down wondering if there was a reloader on this forum that would appreciate the effort.

The last .010"? If you are able to force the case into the gage with your thumb the failure to drop the case into the gage is cause by the case body meaning the diameter of the case needs to be reduced.

I am the fan of datums, most reloaders get a little snarky when datums are mentioned, not from me. The diameter of the case is impossible to measure for a reloader, they have too much pride?

Anyhow, I have chamber gages 'home made' and I have case gages. The case gage, by design, allows the reloader to measure fired and sized cases. The ability of the case gage to measure fired and sized cases is the difference between a case gage and a chamber gage with exceptions. Most chamber gages do not have case head protrusion? Chambers have case head protrusion so my home made gages have case head protrusion.

F. Guffey



There is a way to measure the diameter of the case body with a case gage; problem,