Looking for a case gage

[danny]

Uncle Ed:
Probably because of your postings, I have, by default, included in all of my sizing operations, the "dwell time" in the die, but I am going to make it a standard procedure to be consistent on one of the times that you mention. I have included that dwell time as SOP for quite a while now.

Danny

 

[danny]

Danny, Sometimes that 60s brass was not to spec in the first place but shipped out anyway. I have seen many defect cases in 30-06 that should never have been shipped, but escaped sorry to say.

The problem is that LC isn't synonymous with the same meaning when talking surplus MG ammo compared to when talking National Match ammo, even though it was all called Lake City.

I would caution that your opinion of a full chamber gage may be negative for the wrong reasons. We may not be able to suggest a better gage and that may be the fault of that MG surplus rather than a fault of the gage.

Another follow up question if you know... who cut your chamber?

Many chambers have been a mix of dimensions over the years and some of them are known to be forgiving while others are not. Chambers, brass, dies, and process need to work together and sometimes the dies are easier to change than the other things in terms of overall time and expense.

You are wise to invest in your inspection tools and skills because feeding these guns in a match setting becomes more difficult as the good surplus brass options are getting harder to find.

I don't really have negative thoughts of a full chamber SAAMI type gage, in fact I am sure that I need one.

Before getting to the gaging steps in another posting, I will describe what was happening in my first use of my Sheridan gage.

I was using commercial Winchester .30-06. I have a small quantity of it that I need to use up first. As mentioned, I also tested the gage with new loaded 60s LC ammunition. As mentioned, not all of it, even the cases that seemed not to have been linked for use in machine guns would pass gaging inspection. You mention that some of that was sketchy right out of the gate, and that is a good hint, probably the sole reason for the gaging failures. I also mentioned issues with dinged case rims causing me gaging problems until I figured that out, and that in fact, I oversized cases trying to get them to pass, before I figured out what was up.

I have also figured out that I might have a slight chamber issue with that brass, or maybe the die, ir even both could contribute to the problem with rim interference that I was experiencing. I sold the M1 years ago that fired this brass. Anyway, even though I cleaned up any rim dings, etc. with a file before gaging again, it seemed that I had to really work on some spots a lot, almost like the case was sitting in the gage such that one part of the rim was sitting closer to the interior of the gage and causing further interference. Years ago, Bart Bobbit stated that the Navy team found that it could not reliably correct all issues found in once fired brass during resizing, so they resorted to only using new brass and letting civilians have the empties. Well, most of us don't have a military comparable budget, so that technique is going out the window.

What I am going to have to do is get out my Neco gage and start checking brass before sizing and after sizing to see if anything "funny" is going on.

As mentioned in a prior post, I will get a second full chamber gage, probably the JP, then compare the results between them.

Another thing that I have pretty much decided upon is that since I am sizing for a self loading rifle, not a bolt action or single shot, having a gage that has a full chamber gaging surface all the way back to the rim is a liability. The brass on an M1/M14 clone never goes that deep in.the chamber. What I am going to do to one of the gages is set ut up in my lathe and cut a small rim recess with a boring bar to get the rim issues out of the equation. With that said, I will still pay attention to rim damage and will still clean it up with.a file if it needs it.

Danny

 

[RegionRat]

I don't have the second version JP gage. Interested in hearing how you like it compared to the Sheridan.

 

[danny]

Unfortunately, as far as I have been able to tell through Google searches, JP Enterprises does not make these gauges in .30-06.

Danny

 

[danny]

Can you explain a little about what it is you do not agree with on the Sheridan gage? Which surfaces were you pointing out? Since the Sheridan and Lyman represent a chamber, it isn't clear what surfaces you mean or why those would make you unhappy, so it isn't clear what alternatives to suggest.

I am still going to answer the question above, the last unanswered one. I just need some time to be able to dedicate to it. The answer should be soon, by the end of the weekend.

Danny

 

[dellet]

If I am reading this right, you are checking fully loaded ammo. If that is correct, in a Sheridan gauge, you will also be checking bullet runout.

If the gauge is the slotted slotted version, sometimes you can rotate the round and have it drop the rest of the way in. That would be when the bullet drops into the slot.

Bases/rims can be checked by inserting the case/round in backwards, they should drop in to the 200 line.

Most complaint about the Sheridan is that they fail too many rounds that actually chamber. Specs too tight.

 

[danny]

If I am reading this right, you are checking fully loaded ammo. If that is correct, in a Sheridan gauge, you will also be checking bullet runout.

If the gauge is the slotted slotted version, sometimes you can rotate the round and have it drop the rest of the way in. That would be when the bullet drops into the slot.

Bases/rims can be checked by inserting the case/round in backwards, they should drop in to the 200 line.

Most complaint about the Sheridan is that they fail too many rounds that actually chamber. Specs too tight.

Short reply here:
I was only checking loaded rounds to see what was going on after my resized Winchester cases were failing the check in the Sheridan.

I did end up slipping the case head in backwards to see if the rim would fit, and they all did, easily. They only would bind on the rim when put in the gauge normally, so, as mentioned before, something was going on during firing, or sizing, to get part of the rim to sit closer to the inside of the gage. I will have to get my NECO gage out eventually to inspect the cases.

Danny

I was rotating the rounds as well so that I could make sure that part of the case that could cause an interefernce didn't just happen to allow it to slip in the gage when it would otherwise have failed.

 

[Hoser]

Is this ammo failing your gauge but still fitting in your chamber?

 

[danny]

Is this ammo failing your gauge but still fitting in your chamber?

I don't know. Probably. I am not sizing it to my chamber. I am sizing it to fit SAAMI spec.

Danny

 

[Dusty Stevens]

I don't know. Probably. I am not sizing it to my chamber. I am sizing it to fit SAAMI spec.

Danny

You can get your gunsmith to make you a chamber gage from a saami spec reamer

 

[Hoser]

I don't know. Probably. I am not sizing it to my chamber. I am sizing it to fit SAAMI spec.

Danny

If it fits in your chamber who cares about some mass produced random case gauge?

 

[danny]

If it fits in your chamber who cares about some mass produced random case gauge?

I care because I am not using my chamber to check the cases. I am using the gauge and only the gauge to check the cases.

Danny

 

[danny]

Can you explain a little about what it is you do not agree with on the Sheridan gage? Which surfaces were you pointing out? Since the Sheridan and Lyman represent a chamber, it isn't clear what surfaces you mean or why those would make you unhappy, so it isn't clear what alternatives to suggest.

Here, from the Sheridan website, is a description of the gauging surfaces and gauging dimensions:

"The face of the gauge is equal to the max acceptable headspace length of a SAAMI spec chamber. The middle step is the minimum headspace length of a SAAMI spec chamber. An in spec firing chamber will be somewhere in the range of these 2 slots. To make brass fit any SAAMI spec firing chamber, it should be at the level of, or shorter than the middle step.

The lowest step is the minimum SAAMI spec brass length. If brass is made between the middle step, and and lowest step, it should be in spec, and also fit"

What I find confusing and don't like is the fact that they are using three gauge steps, which is opposite of any gauges made that I know of, which merely have two steps, a minimum case length, the lower one, and a maximum one, the back face of the gage. I find it difficult to use that middle surface as a maximum gauging surface for creating SAAMI minimum cases as compared to the rear face on other gauges.

Danny

 

[RegionRat]

The lowest step is the minimum SAAMI spec brass length.

Yes, but be sure to avoid swapping the terms "brass" and "chamber", those two specifications are not the same.

When we say "brass" we imply the cartridge, which has its own specification dimensions.

What I find confusing and don't like is the fact that they are using three gauge steps, which is opposite of any gauges made that I know of, which merely have two steps, a minimum case length, the lower one, and a maximum one, the back face of the gage. I find it difficult to use that middle surface as a maximum gauging surface for creating SAAMI minimum cases as compared to the rear face on other gauges.

I believe your consternation is the relationship between the chamber drawing versus the cartridge drawing. One of the steps this brand of gage gives you is from the cartridge specs, the other two are from the chamber.

This is not a bad thing and the proper thing to include in this style of gage otherwise you force the user to also measure this again some place else. Why not include it here?

I will advise to study both specs for your cartridges. While there are things about the SAAMI specs I personally don't like, they are online and free to study.

The purpose to the two chamber steps, is they represent the distance from the bolt face to the shoulder datums with the difference between the two chamber gages that a gunsmith is supposed to use when setting the chamber. To be complete with any chamber gage, they have to show these two. However, that third step is also valuable to have in the same tool.

By including the MIN BRASS step, you can tell when a cartridge is so short that it is out of specifications. There is no law that says you cannot pull the trigger on a undersized piece of brass, but it isn't good for the brass on one hand, and taken too far can add other risks on the other hand.

From the printed instructions on the Sheridan Case Gage (bold emphasis is me pointing out the issue)

A - MAX CHAMBER DIMENSION (NO GO GAGE)
B - MIN CHAMBER DIMENSION (GO GAGE)
C - MIN CARTRIDGE DIMENSION (SAAMI SPEC)

So Danny, the gage isn't the issue and a different one made to SAAMI isn't likely to make you happy either. If you want to, you can ignore a step, but then I am worried about your understanding.

BTW, these steps are all about shoulder datum lengths, but diameters are just as critical.

In designs that have taper, diameters between chambers, dies, and brass, all affect each other. We cannot adjust a die for diameter independently from the length with a tapered design. When you move the die adjustment up or down, you include some amount of diameter change, it is just smaller change based on the trigonometry.

When we talk about shoulder datum lengths, we are generally throwing around thousandths of an inch, when we talk about diameters we break out the micrometers and talk about ten-thousandths of an inch.

Only a jump to another brand of custom die, or a small base die for example, will significantly change the diameter issues. It takes very little to create a reliability issue with diameters compared to lengths. Learning to inspect both sets of issues with or without the above gage would be my advice.

Best to have the chamber, brass, and dies coordinated up front. YMMV

https://saami.org/wp-content/upload...99.4-CFR-Approved-2015-12-14-Posting-Copy.pdf

 

[danny]

Yes, but be sure to avoid swapping the terms "brass" and "chamber", those two specifications are not the same.

When we say "brass" we imply the cartridge, which has its own specification dimensions.


I believe your consternation is the relationship between the chamber drawing versus the cartridge drawing. One of the steps this brand of gage gives you is from the cartridge specs, the other two are from the chamber.

This is not a bad thing and the proper thing to include in this style of gage otherwise you force the user to also measure this again some place else. Why not include it here?

I will advise to study both specs for your cartridges. While there are things about the SAAMI specs I personally don't like, they are online and free to study.

The purpose to the two chamber steps, is they represent the distance from the bolt face to the shoulder datums with the difference between the two chamber gages that a gunsmith is supposed to use when setting the chamber. To be complete with any chamber gage, they have to show these two. However, that third step is also valuable to have in the same tool.

By including the MIN BRASS step, you can tell when a cartridge is so short that it is out of specifications. There is no law that says you cannot pull the trigger on a undersized piece of brass, but it isn't good for the brass on one hand, and taken too far can add other risks on the other hand.

From the printed instructions on the Sheridan Case Gage (bold emphasis is me pointing out the issue)

A - MAX CHAMBER DIMENSION (NO GO GAGE)
B - MIN CHAMBER DIMENSION (GO GAGE)
C - MIN CARTRIDGE DIMENSION (SAAMI SPEC)

So Danny, the gage isn't the issue and a different one made to SAAMI isn't likely to make you happy either. If you want to, you can ignore a step, but then I am worried about your understanding.

BTW, these steps are all about shoulder datum lengths, but diameters are just as critical.

In designs that have taper, diameters between chambers, dies, and brass, all affect each other. We cannot adjust a die for diameter independently from the length with a tapered design. When you move the die adjustment up or down, you include some amount of diameter change, it is just smaller change based on the trigonometry.

When we talk about shoulder datum lengths, we are generally throwing around thousandths of an inch, when we talk about diameters we break out the micrometers and talk about ten-thousandths of an inch.

Only a jump to another brand of custom die, or a small base die for example, will significantly change the diameter issues. It takes very little to create a reliability issue with diameters compared to lengths. Learning to inspect both sets of issues with or without the above gage would be my advice.

Best to have the chamber, brass, and dies coordinated up front. YMMV

https://saami.org/wp-content/upload...99.4-CFR-Approved-2015-12-14-Posting-Copy.pdf

I have read all of that and appreciate your lengthy and considerate reply. I understand all of that, and always have, so no worry. I guess that when you get down to it, what I wish was that the gauge merely measured CARTRIDGE minimum and maximum , and we are talking about distance from the case head to the SAAMI datum point here, as well as the CARTRIDGE radial dimensions, that is, will it fit in a SAAMI minimum chamber (which it already does), and is slotted (mine is). Sometimes simpler is better. As my eyes age, they don"t get better, even with glasses, so having the two step gage would be simpler to use. Gauging maximum CARTRIDGE length would be easier at the rear of the gauge. Generally, I have headspace gauges, so if need be, I could figure out my headspace and don't really need gauging surfaces for chamber length on the gauge. It is a great gauge and I am either going to have to modify my technique and/or the gauge itself to suit my needs. I still plan on making a case rim relief in the gauge on my lathe. That is not something I would do for a non-autoloading rifle.

Danny

 

[dellet]

Simply ignore the middle step, it’s just a point of reference if you don’t like it.

Headspace is generally a .010” min/max window. The Sheridan gauge gives you min .000” top surface, 005” center step, max .010” bottom surface. It’s simply a second point of reference.

The Sheridan will also measure max cartridge length as the gauge is cut to max SAAMI length. If the bullet sticks out the bottom it’s too long. This only applies to bullets that will not jam before reaching magazine length.

 

[RegionRat]

I have headspace gauges, so if need be, I could figure out my headspace and don't really need gauging surfaces for chamber length on the gauge. It is a great gauge and I am either going to have to modify my technique and/or the gauge itself to suit my needs. I still plan on making a case rim relief in the gauge on my lathe. That is not something I would do for a non-autoloading rifle.

Danny, if you drop your chamber GO, NO-GO, gages into your Sheridan gage, you may change your mind about it.

That extra step they cut in can be ignored and really shouldn't bother you. In essence, if you ever were to throw in a cartridge that went below that level, you may be glad you had it.

If you had rim issues, I hope they were rare and not across the whole batch. Cutting the gage is something you can do if you want to, but it makes no sense to ruin the gage to clear damaged rims. If for example, a cartridge hangs on the gage due to the rim, then you got a warning to look further for the reasons and make decisions. If you cut that away, yes it will drop deeper into the gage, but then you loose the warning that you may have an issue with your extractor, gas, or brass.

Good Luck in any case. Hope you keep The Olde Wooden Guns in action on the range. I really dig the CMP format, but would never run a Garand in XTC just due to how much TLC it takes to keep one tuned at 600. When I was young, the guns I ran in XTC didn't belong to me, but I knew how much work and expense went into them. I held off due to career demands and went the AR route once I got to a point in life where I was able to shoot in matches again. Good Luck and Best Wishes.

 

[danny]

Danny, if you drop your chamber GO, NO-GO, gages into your Sheridan gage, you may change your mind about it.

That extra step they cut in can be ignored and really shouldn't bother you. In essence, if you ever were to throw in a cartridge that went below that level, you may be glad you had it.

If you had rim issues, I hope they were rare and not across the whole batch. Cutting the gage is something you can do if you want to, but it makes no sense to ruin the gage to clear damaged rims. If for example, a cartridge hangs on the gage due to the rim, then you got a warning to look further for the reasons and make decisions. If you cut that away, yes it will drop deeper into the gage, but then you loose the warning that you may have an issue with your extractor, gas, or brass.

Good Luck in any case. Hope you keep The Olde Wooden Guns in action on the range. I really dig the CMP format, but would never run a Garand in XTC just due to how much TLC it takes to keep one tuned at 600. When I was young, the guns I ran in XTC didn't belong to me, but I knew how much work and expense went into them. I held off due to career demands and went the AR route once I got to a point in life where I was able to shoot in matches again. Good Luck and Best Wishes.

Hi,
Thanks. I don't really shoot across the course, and I haven't for quite a while, since the time that they changed whatever they did in rapid prone. If I would shoot across the course, it would primarily be with an AR. I might now and again shoot an M14 Clone, or an M1, but an M1 is tricky for me, as I shoot lefty. I shoot Long Range Service Rifle, or Mid-Range Service Rifle. I 90% use an M14 Clone. Sometimes I use an AR, including 1000, as well as an M1, but I have never tried an M1 at 1000. That has to change...soon.

Danny