The Case Guage Two Step..

[RN]

Ok..

Being somewhat new to reloading I feel like I have read all the appropriate info, bought ok stuff,(pic below)and hopefully asked the approprte questions. What I am learning is that reloading is an art as much as it is a science and therefore I will never know everything.

So.....I have another question regarding my case guage selection. When I started loading for my .223 I purchased a JP enterprises case Guage. I thought it would do everything!! Now, from what I understand, the JP will measure diameter and chamber issues but I will need the Dillion to measure headspace and overall length. JP told me Thier guage will not measure headspace so I bought the Dillion for that. Does that seem right?

 

[fguffey]

I have take off barrels, I have cut off barrels and I have new barrels. I do not have tomato stakes. I do not hesitate to cut the stub from a barrel to make a chamber gage. I modify L,E, Wilson case gages to case gages meaning I measure the diameter if a case with a Wilson case gage.

The Wilson case gage is a very accurate gage, I use a straight edge and feeler gage when deterring the length of a case from the datum/shoulder to the head of the case. It is possible to stand a case on a flat surface and [lace the case gage over the case, when the case gage is supported by the shoulder/datum contact the reloader can measure the gap between the flat surface and bottom of the die.

Using barrels, the reloader needs to know the case head protrusion of their chamber or understand transfers and standards.

F. Guffey

I will need the Dillion to measure headspace and overall length.

No clue, my cases do not have head space, my cases have 2 lengths, one is from the datum to the case head and the other from the mouth of the case to the case head. If everything had head space and all gages were head space gages I believe everyone would be confused.

F. Guffey

 

[blarby]

I hate to say this, but I think the RCBS precision mic does everything you are looking for.

It is more expensive, yes.

Only "case" measure I know of that lets you "dial in" cartridge measurement to your chamber all in one tool.

An OK video of how this works :

https://www.youtube.com/watch?v=02p5BNhEh1w

 

[RN]

Oh..The reasoning behind just now buying the Dillion is because while shooting my reloads at the range the other day I had one FTF and the case kinda stuck my bolt closed..I got it out and it had no primer strike and seemed to be within specs. I brought it home and it passes the JP no problem. I'm thinking maybe it would not pass the Dillion..Maybe the headspace is off..All other rounds went bang and were fantastically accurate.Am I correct in regards to the two gauges?

JP measures chamber stuff, diameter, etc?

Dillon measures Headspace?

 

[Reloadron]

I assume you have one of these. From our friends at JP we get this:

This gauge is cut with a .223 Wylde chamber finishing reamer, and will
give a reliable check of ammunition used in rifles chambered for either the
.223 Remington SAAMI specifications or the 5.56 NATO specification.

The merit to the JP gauges is they are cut using a chamber reamer. Many similar gauges like the Wilson gauges will measure a few case dimensions (Go/NoGo) but will not measure the base dimension. Now if you bought the Dillon Rifle headspace case gage I really don't see what that gauge will tell you that the gauge you have won't.

The main reason a case won't easily chamber is the case was not correctly sized. Seldom, very seldom, have I seen a hard closing bolt on new factory ammunition or a stuck case.

JP measures chamber stuff, diameter, etc?

Yes, it does and it also should measure the case overall length as well as the base of the case to a datum point on the case shoulder. The gauge should have steps on both ends. I don't have a JP gauge but most all of these gauges are the same idea.

The case should fit into the gauge and the case head should not extend beyond the upper step on the base with being flush with the lower step preferred. The case mouth should not extend beyond the upper step on the other end of the gauge with being flush with the lower step preferred. Again I don't have a JP gauge but here are a few examples using an old Forrester 308 gauge.





That be similar to what you have?

Ron

 

[jim243]

The L.E. Wilson gives you the correct shoulder as well as the correct head space if your rifle is in spec.

Jim



This is a NO-GO bolt will not close.

 

[RN]

Thanks Ron..On the JP there is not upper and lower step..I called them and according to the guy that answered the phone the guage does not check headspace. That's where I'm confused and why I purchased the Dillion as well.. I would think that JP would have to let you know if head space was incorrect because if it didn't what good is it. It even says it checks head space on the website. It's supposed to be the best guage out there because it does both..Diameter and Headspace unlike the others..

There must be some reason he said that..Maybe it checks it but does not measure it? I'm lost..Once I figure it out know anyone who wants to buy a brand new Dillion?

From JP's Website:

Any rifle with a tight chamber is going to suffer with out-of-spec ammunition, and most operational failures in self-loading rifles can be traced back to this problem. If you're a reloader, you know this better than most. Unlike other gauges available, the precision JP Case Gauge is cut with an actual match chamber finish reamer so it not only checks head space but also case diameter relative to typical match-grade chambers and min/max case length on top of that. What's more, the fact is that most other gauges indicate minimum and maximum case headspace as defined by SAAMI, which still allows for a possible interference between a maximum-sized cartridge and a minimum allowable chamber. While this would not be an issue in a bolt gun, it will bring everything to a stop in a self-loader. Our gauge insures that the maximum cartridge indicated by the gage is still within the minimum SAAMI allowable chamber. In other words, if your ammunition passes our gauge, it absolutely will fit the chamber. It's the only sure way to know that your ammo is compatible.

 

[Otto]

....the other day I had one FTF and the case kinda stuck my bolt closed..I got it out and it had no primer strike and seemed to be within specs. I brought it home and it passes the JP no problem.

Stuck cases? Yeah, sounds like you need to turn down the sizer a bit more.
Here's a guy that was having the same problem with the JP ammo checker. http://www.brianenos.com/forums/index.php?showtopic=179160
I assume you're loading for an AR.

I use the above Wilson myself along with the Hornady.

 

[Reloadron]

Thanks Ron..On the JP there is not upper and lower step..I called them and according to the guy that answered the phone the guage does not check headspace. That's where I'm confused and why I purchased the Dillion as well.. I would think that JP would have to let you know if head space was incorrect because if it didn't what good is it. It even says it checks head space on the website. It's supposed to be the best guage out there because it does both..Diameter and Headspace unlike the others..

There must be some reason he said that..Maybe it checks it but does not measure it? I'm lost..Once I figure it out know anyone who wants to buy a brand new Dillion?

From JP's Website:

Snag yourself a Wilson as jim243 was kind enough to post some images of.

I wasn't sure after reading about the JP gauge exactly what it would tell you beyond it was cut from a chamber reamer. I was unsure as to the steps you see in mine and Jim's images.

On a final little note some members will tell you that a cartridge does not have a headspace dimension. They base this on looking at the SAAMI Drawings for Cases Like The 223 Remington Case. The link shows both case and chamber drawings for a 223 Remington. You can see that only the chamber drawing has a headspace reference (circle enclosing a x). The cartridge has a corresponding number that is not called out as "headspace". That said the guys making these gauges do in fact use the term headspace when referring to their cartridge gauges. I started using the term since it is widely accepted. Just don't let things confuse you.

Ron

 

[Otto]

On a final little note some members will tell you that a cartridge does not have a headspace dimension.

For the love of god....let's not start that debate.

 

[RN]

I read that whole thread and it seems if anything the JP is hard to read.. One thing to mention is that he kept mentioning how the JP is cut with an actual remer..Well, for me that does no good as my Daniel Defense's chamber is formed by cold hammer forging..Im guessing to NATO Mil spec?

 

[Reloadron]

I read that whole thread and it seems if anything the JP is hard to read.. One thing to mention is that he kept mentioning how the JP is cut with an actual remer..Well, for me that does no good as my Daniel Defense's chamber is formed by cold hammer forging..Im guessing to NATO Mil spec?

OK, we don't want to get way, way off topic so in a nutshell Cold Hammer Forging is merely a process used to manufacture a barrel. Many processes can be used and each process has some good and bad points. Cold hammer forging is a process and that is all it is, one of several processes that can be used. Taken from one manufacturer:

Our previous standard chrome lined 4150 barrels were made with a button
broach process. The barrel starts as a bar that is bored using a gun drill. The
lands and grooves of this process were made by pulling a button through the
bore. Finally the barrel was contoured on a lathe.

Cold hammer forged barrels utilize the same steel, only they are manufactured
differently. The barrel starts again as a bored out bar, however both the bore and
outside diameter are oversized. This oversized barrel is inserted into a hammer
forging machine. A mandrel is fed along with the barrel though the machine. Rotary
hammers forge the barrel around the mandrel creating the final bore diameter and
forming the lands and grooves. The barrel is then contoured and fished.

The cold hammer forge process offers distinct advantages. The process reduces
the outside diameter of the barrel without removing material. This increases the
density of the steel, making it stronger and more rigid. The crystalline structure
of the steel is realigned to the desired rifle twist. Finally pulling a button broach
through the barrel creates tiny pot and tear marks through the bore; whereas
the hammer forging process leaves a super smooth surface throughout the bore,
offering less resistance on the projectile.

The chamber is cut using a chamber reamer. The chamber reamer is just a tool that removes metal and thus "cuts" a chamber in a rifle barrel in this case.

Believe me that your Daniel Defense barrel chamber was cut with a chamber reamer. The process used to manufacture the barrel was a Cold Hammer Forged Process.

All case gauges like the Wilson, JP, Forrester and similar are cut using a reamer. While not the best way to show this the below image should give an idea:



A chamber reamer is pictured in the center. Below is a case gauge with a reamer shoved through it as if the reamer cut the gauge:



That is what JP is saying. That an actual SAAMI Specification reamer is used to cut their case gauges. In the above image the Forrester Gauge in reality was not cut with a true chamber reamer, it was cut with a reamer, just not a SAAMI Specification reamer. While some of the dimensions of the above gauge are accurate the case diameter isn't to SAAMI Specification. Truth is that above reamer will actually wobble around in that gauge but you get the idea I hope.

These are the JP Case Gauge instructions which pretty much suck.

Ron

 

[grogetr]

I have only loaded 9mm so far and am now starting to get what I need for 223 reloading. Do you have to have a case gage or can you reload without it. This will be for an AR

 

[Reloadron]

I have only loaded 9mm so far and am now starting to get what I need for 223 reloading. Do you have to have a case gage or can you reload without it. This will be for an AR

When reloading 223 for an AR if you want a case gauge the everyday L.E. Wilson Case Length Headspace Gage 223 Remington is a good choice, as good as any. Keep in mind that people have been hand loading 223 Remington for many years before tools like these gauges ever came about. Years ago some hand loaders made their own gauge and still do today but making a gauge requires tooling and machinery the average home hand loader doesn't have.

I hand load 223 for several AR rifles as well as a bolt gun. While I do have SB (Small Base) 223 dies I normally just use the same everyday RCBS full length sizing dies I used for years. Just make sure you set the dies up per the die manufacturers instructions.

The case gauge is more, in my opinion, a nice to have tool but not a absolutely necessary tool.

Ron

 

[Rule3]

When reloading 223 for an AR if you want a case gauge the everyday L.E. Wilson Case Length Headspace Gage 223 Remington is a good choice, as good as any. Keep in mind that people have been hand loading 223 Remington for many years before tools like these gauges ever came about. Years ago some hand loaders made their own gauge and still do today but making a gauge requires tooling and machinery the average home hand loader doesn't have.

I hand load 223 for several AR rifles as well as a bolt gun. While I do have SB (Small Base) 223 dies I normally just use the same everyday RCBS full length sizing dies I used for years. Just make sure you set the dies up per the die manufacturers instructions.

The case gauge is more, in my opinion, a nice to have tool but not a absolutely necessary tool.

Ron

Pretty much sums it up for me also. I have one for 223 and 308.

 

[HJ857]

I have a JP case gauge and it absolutely has a high/low step on both ends of the gauge. It functions exactly like the LE Wilson unit except that the JP is cut to SAAMI spec diameter.

The statement by JP Rifles that the gauge does not measure case sizing is very odd. That's exactly what a case gauge does. Something is amiss.

The malfunction described could also be a problem in the neck of the case, buckling at the shoulder or crimp area. It may be worth looking at the seater die to be sure it's set correctly.

 

[fguffey]

....the other day I had one FTF and the case kinda stuck my bolt closed..I got it out and it had no primer strike and seemed to be within specs. I brought it home and it passes the JP no problem.

It is possible the extractor did not jump the rim of the case. I have seen Mauser owners attempt push feed on their control feed rifle.

I am the fan of the chamber gage, it is possible to modify the case gage to measure like a chamber gage, it is possible to modify a go-gage to a go-to infinity gage, Problem? Period correct?

F. Guffey

 

[Reloadron]

I have a JP case gauge and it absolutely has a high/low step on both ends of the gauge. It functions exactly like the LE Wilson unit except that the JP is cut to SAAMI spec diameter.

The statement by JP Rifles that the gauge does not measure case sizing is very odd. That's exactly what a case gauge does. Something is amiss.

The malfunction described could also be a problem in the neck of the case, buckling at the shoulder or crimp area. It may be worth looking at the seater die to be sure it's set correctly.

Looking at the JP Case Gauge like this example from Brownells the gauge does look to have steps? Beats me as I don't have one. HJ857 can you or someone with these gauges post a picture that clearly shows the steps so the OP will know better what he has?

Thanks
Ron

 

[Potatohead]

I dont know much, but I do wish to tell you that when you are trying to see which step your case comes to in the gauge, don't try to see it...feel it! Maybe it's my eyesight (or lack thereof) but I found it much easier to run my finger across to see if the case was sitting to low, in the middle, or to high...

 

[Slamfire]

On the JP there is not upper and lower step..I called them and according to the guy that answered the phone the guage does not check headspace.

I wonder if the representative meant check chamber headspace.

For bolt guns, a fired case blows itself to the chamber and stays chamber dimensions after extraction. Whatever shrinkage actually occurs is below anything I can measure. If you have not noticed, by the time your hand reaches the bolt on a bolt gun, barrel pressure is zero. Barrel pressure drops to zero in milliseconds.

However, gas guns unlock when there still is residual pressure in the barrel, and this is deliberate. Designers want enough residual pressure to help “pop” the case out of the chamber. Obviously they don’t want so much residual pressure that the case separates or ruptures, so timing is very important and studied.

These are from Chin:












So, because your AR15 actually extracts while there is pressure in the barrel, any case that comes out of that barrel will be stretched, and it won’t be the exact size of the chamber.

These are 308 Win cases I fired 23 times in my match M1a. I lubricated these cases and never experienced a case head separation. Many shooters experience case head separations in under five reloads in these mechanisms with dry cases and dry chambers. What happens with dry cases and dry chambers is that after the primer is struck, the case neck and shoulder fold out and adhere to the chamber walls, than as pressure builds, the midsection of the case is stretched to the bolt face. With lubricated cases, after the primer is struck, the case slides to the bolt face because the friction between chamber and case is so low that the case neck and shoulder cannot adhere to the chamber walls. This eliminates case sidewall stretch.

But, the shoulders are affected during extraction. Here I measured the shoulder to base distance on these lubricated cartridges and found just how much that shoulder distance had moved during extraction.



My lubricated cases were sized to 1.630”, which is the minimum dimension on a Wilson gage, but on extraction, they were longer. What I believe is going on is during extraction, during that low pressure residual extraction period, the shoulders are still under pressure to fit the shape of the chamber, but the chamber is growing longer! So, attempting to measure chamber headspace by measuring the base to shoulder measurement of a fired cartridge case, is doomed to failure in any gas gun. It might work in a long recoil gun, it would have to be a mechanism where unlock and extraction occur when barrel pressures are zero.

This advanced primer blowback mechanism was used in the Polsten cannon, among others. Since this is a blowback, there is no locking mechanism (!) and there is a lot of travel in that chamber, I really doubt there would have been any case shoulder left on extraction. For this mechanism to work, in fact for all of these that were manufactured, the whole cartridge had to be greased!

 

[blarby]

^^^^ This needs to go in the "library"

Nicely done !

 

[243winxb]

So, because your AR15 actually extracts while there is pressure in the barrel, any case that comes out of that barrel will be stretched, and it won’t be the exact size of the chamber.

I disagree. I did a lot of measuring on my M16A1 carbine, no stretching (longer). I feel the above quote woudl be true for an M1A, from what i read on the subject.

 

[Slamfire]

Take a look at this DTIC document: Understanding Extractor Lift in the M16 Family of Weapons
www.dtic.mil/ndia/2003smallarms/din.ppt

The Army had to grease their cases to show that residual blowback pressures were keeping cartridges on the bolt face during extraction. Because there is residual pressure on extraction, I would not expect extracted cases to be a true measure of chamber headspace.

I will agree that the AR15 mechanism is easier on the cartridge case than the Garand mechanism, and that may be why your cases don't show stretch. But that may not be true for all AR's.

The last video shows the Garand cycles 25% faster than a AR15:

M1 Garand at 1200 frames per second

https://imgur.com/a/3kabN

 

[HJ857]

Just in case it could be useful to the OP.

 

[RN]

Thanks guys..Great comments and advice..

@HJ857..I have the same guage in the same color and even as I look at yours I see an upper step but no lower "step". Both the equal ridges along the top represent an upper step but there is no lower step to stay between. Make sense? On a wilson or dillion there are two distinct steps..one upper and one lower so as to be able to guage headspace. Some even say you can measure shoulder bump with the dillion and wilson. Not going to happen with the JP.

With the JP it's either below or above the ridges..Not really in between..That's my issue with it and if there is a step somewhere in there it's hard as heck to see consistanly..Great guage though for checking diameter and chamber fir though..I think having both will serve me well..