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Cartridge Gauge - Before/After Bullet Seating

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  • Rathmatik

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    Howdy,

    I just tried out my new RCBS Matchmaster Seater die for 6.5 Creedmoor with Hornady brass and Sierra 130gr TGK bullets. I really like the features of this die, and the micrometer appears to be spot on.

    Now, I'm seeing something that I'm unsure whether it should be concerning or not. My cases are fitting into my Hornady Cartridge Gauge just fine after resizing. I have had a few out of 20 rounds that I just made that no longer fit the gauge after seating the bullet with this new die. I tried giving them a little nudge in the gauge, which then scraped the case near the bottom of the shoulder.

    First off, what would be causing this happen? Second, is this concerning? All of the rounds were easy to chamber in my Bergara B-14 HMR.

    This would almost seem like the cases are growing in length after seating, or is it an issue with runout? I don't have a runout measuring tool, unfortunately.
     

    Dawico

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    If they fit your chamber they are fine.

    Crimping seems to be the number one cause of cartridges not fitting the case gauge. If you are crimping stop.

    If them not fitting the case gauge really bothers you throw the gauge away. Problem solved. I've never owned one or felt the need to. I use my firearm's chamber since that's all that matters.
     

    Rathmatik

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    If they fit your chamber they are fine.

    Crimping seems to be the number one cause of cartridges not fitting the case gauge. If you are crimping stop.

    If them not fitting the case gauge really bothers you throw the gauge away. Problem solved. I've never owned one or felt the need to. I use my firearm's chamber since that's all that matters.

    Haha, yeah I suppose that would work too. I'm definitely not crimping, as I don't do that for bottleneck cartridges. The RCBS Matchmaster seater die actually doesn't have a way to crimp, anyway ;)
     

    Deavis

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    Yes, throwing away a means to check cartridges versus an established industry specification in exchange for ammo that may only work in one gun and checking it is way harder... yeah that is a win. It is like throwing away the manual to your car because all those troubleshooting steps take too long.

    If it doesnt fit the gage, there is an issue. Figure it out and actually know your process better. If it happens after seating a bullet then it is likely you have a diameter issue that a pair of calipers can detect. What is the pre and post neck diameter? Possible you have a neck thickness issue? A little math will tell, take some measurements and post them.
     

    rmantoo

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    Check your neck tension/sizing carefully.

    Sounds to me like your neck tension may be too high (necks sized too small, or projectiles possibly sized too big) and seating the pills may induce just enough deformations to throw 1 in 20 out of spec.

    Just one thing to check.
     

    rmantoo

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    Just an off the wall reply here.
    A clean case gauge can be your best friend.
    A dirty case gauge can make chase problems that don’t exist.
    Been there, done that.

    100% agree.

    if you don’t already, I'd suggest wiping down any calipers or gauges immediately before and after each use...
     

    rotor

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    Rifle case gage literally is for adjusting the resizing die and letting you know if the case is properly trimmed. It is not an ammo checker. It is specifically for the case. From what I can tell you are using the case gage on a fully loaded round with a bullet loaded. To make sure you meet sammi spec you need an ammo checker and Lyman makes one. I would not throw out the case gage but I might consider an ammo checker in addition. I would bet that your rounds are all good. Pistol gages are different and I use pistol gages as an ammo checker.
     

    Rathmatik

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    I did some measurements to compare rounds that fit the gauge fine vs. the ones that didn't, and they were identical. Perhaps the gauge needed some cleaning, so I'll try that. I will do more measurements before seating next time too so I can have some additional data to verify.
     

    Rathmatik

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    How low are yo running your die down?

    I lowered it to hit the shellholder, and then about 1.5-2 turns up (to make space for the case length and also center the micrometer in front). It was enough to get the case fully engaged before hitting the seating stem.
     

    Rathmatik

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    Rifle case gage literally is for adjusting the resizing die and letting you know if the case is properly trimmed. It is not an ammo checker. It is specifically for the case. From what I can tell you are using the case gage on a fully loaded round with a bullet loaded. To make sure you meet sammi spec you need an ammo checker and Lyman makes one. I would not throw out the case gage but I might consider an ammo checker in addition. I would bet that your rounds are all good. Pistol gages are different and I use pistol gages as an ammo checker.

    Well, that's not exactly true. There are both case/headspace gauges for rifle, which do what you're suggesting, as well as cartridge gauges or ammo checkers that are meant to verify that the round will chamber against SAAMI specs. I have the Hornady headspace gauges that attach to calipers, so I was able to configure my sizing die down enough to yield .001-.002" setback. I also have the cartridge gauge, which you can use to make sure your full length resizing is correct (if you use it before resizing, it won't fit in the gauge), and then again after completing the round to verify it will still chamber in most rifles.

    I'll post again soon (probably next week) with some updated measurements/tests. It might also be time to grab a runout tool to make sure that isn't the problem either.
     
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    rotor

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    Well, that's not exactly true. There are both case/headspace gauges for rifle, which do what you're suggesting, as well as cartridge gauges or ammo checkers that are meant to verify that the round will chamber against SAAMI specs. I have the Hornady headspace gauges that attach to calipers, so I was able to configure my sizing die down enough to yield .001-.002" setback. I also have the cartridge gauge, which you can use to make sure your full length resizing is correct (if you use it before resizing, it won't fit in the gauge), and then again after completing the round to verify it will still chamber in most rifles.

    I'll post again soon (probably next week) with some updated measurements/tests. It might also be time to grab a runout tool to make sure that isn't the problem either.
    Which part of what I posted is not true? You are using the case gage correctly when you use it right after resizing the case and as long as it fits perfectly in length , height, etc. your resizing die is correct. Your description though is that with a bullet loaded it doesn't quite fit the case gauge. The case gage in rifle is designed for the case, not the loaded round. An ammo checker now will show if the completed round meets saami specs. There is a video on youtube (which I can't find right now) where a guy shows a completed round that fits in a case gauge but not in an ammo checker.
    I suspect though that your completed round is getting a slight swelling with a bullet loaded and would probably pass the ammo checker test. The only other suggestion is to use something like the Lee factory crimp die and with just the lightest pass see if it now allows a completed cartridge to easily go into a case gage. My main point though is that a case gage is close to but not a replacement for an ammo checker.
     

    Rathmatik

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    Which part of what I posted is not true? You are using the case gage correctly when you use it right after resizing the case and as long as it fits perfectly in length , height, etc. your resizing die is correct. Your description though is that with a bullet loaded it doesn't quite fit the case gauge. The case gage in rifle is designed for the case, not the loaded round. An ammo checker now will show if the completed round meets saami specs. There is a video on youtube (which I can't find right now) where a guy shows a completed round that fits in a case gauge but not in an ammo checker.
    I suspect though that your completed round is getting a slight swelling with a bullet loaded and would probably pass the ammo checker test. The only other suggestion is to use something like the Lee factory crimp die and with just the lightest pass see if it now allows a completed cartridge to easily go into a case gage. My main point though is that a case gage is close to but not a replacement for an ammo checker.

    I think you may have just misinterpreted what I said I used. I used the Hornady cartridge gauge, which does perform the "ammo checker" job. This is Hornady's description of this gauge:

    Hornady Lock-N-Load® Cartridge Gauges allow the user to check their cases and ammo to ensure a correct fit in SAAMI chambers

    And on Midway:
    Hornady Lock-N-Load Cartridge Gauges allow the user to check their cases and ammo to ensure a correct fit in SAAMI chambers. Cut to SAAMI maximum tolerances, these gauges will ensure your ammo will fit into any correctly cut chamber.

    Unless I'm completely wrong on what this gauge is designed for. It doesn't have the same min/max ledges that the Wilson case gauges have.
     

    rotor

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    I think Hornady is giving some slightly incorrect info but I could not get a copy of their instruction sheet off of their website. I did go to the masters, Wilson and urge you to read their instructions for their case gage. I would like to see a copy of the Hornady instructions but can't find them anywhere. I think I will email them for a copy or if you have one I would like to see it.

    Note their comment that the gauge does not measure body diameter (which is why I believe your cartridges had a problem). I think that the Hornady is probably a copy of the Wilson gage. There is always a lot of confusion on what a case gage can and can not do vs an ammo checker. I believe that your ammo would check out good in an ammo checker but who knows.
     

    rotor

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    Got this from Hornady today

    "I'm sorry but we do not have any instruction manuals for the Cartridge gauge. However what you are looking for is to have the head of the case flush with the top of the gauge. If the head drops below that lower grove it is under the SAAMI spec. standards for headspace settings. If the head of the case is above flush the round is long in the headspace. This could be an issue in allowing your firearm to chamber the rounds. This of course is dependent on your true headspace setting in your firearm. Thanks "

    Not very helpful. I would stick to the info posted on Wilson gages as most accurate.
     

    Deavis

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    Got this from Hornady today

    "I'm sorry but we do not have any instruction manuals for the Cartridge gauge. However what you are looking for is to have the head of the case flush with the top of the gauge. If the head drops below that lower grove it is under the SAAMI spec. standards for headspace settings. If the head of the case is above flush the round is long in the headspace. This could be an issue in allowing your firearm to chamber the rounds. This of course is dependent on your true headspace setting in your firearm. Thanks "

    Not very helpful. I would stick to the info posted on Wilson gages as most accurate.

    You aren't right and you aren't wrong. Here is the simple answer, either the gage meets the SAAMI specs for ammo or it doesnt. A properly cut gage will meet the SAAMI spec for all characteristics (min, max, or in between) for AMMO. There is no difference in names wrt the spec, your gage either does or does not meet it.

    A proper gage, which pretty much everyone makes, is a max ammo spec gage. Remember min chamber is greater (or equal to) than max anmo spec. If the gage is max ammo, then it will fit in any chamber that meets the SAAMI spec for chambers. Dont care what they call the gage, the important thing is what spec it is cut to. If the name helps you, great. Gages used for ammo that meet the max ammo spec are good for everything we do and, in 99% of cases, even a min chamber spec would work.
     

    rotor

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    You aren't right and you aren't wrong. Here is the simple answer, either the gage meets the SAAMI specs for ammo or it doesnt. A properly cut gage will meet the SAAMI spec for all characteristics (min, max, or in between) for AMMO. There is no difference in names wrt the spec, your gage either does or does not meet it.

    A proper gage, which pretty much everyone makes, is a max ammo spec gage. Remember min chamber is greater (or equal to) than max anmo spec. If the gage is max ammo, then it will fit in any chamber that meets the SAAMI spec for chambers. Dont care what they call the gage, the important thing is what spec it is cut to. If the name helps you, great. Gages used for ammo that meet the max ammo spec are good for everything we do and, in 99% of cases, even a min chamber spec would work.
    Well, we can drag this out forever I guess but for rifles, a case gauge is not an ammo checker, if you note that the gauge does not even include the bullet. An ammo checker makes sure the case and bullet in a completed cartridge meet sammi specs. Do you have a rifle case gauge that actually encompasses the bullet in the case gauge? Pistol gauges do but I don't own a rifle gauge that does. Even Wilson (they invented the gauge) says " the cartridge case gage is not made to measure body diameters or neck diameters". That is why some ammo that fits a case gage fails the ammo checker. Ammo checkers check the entire cartridge (bullet and brass). This is all academic and many people are confused by it as well.
    I was not very happy with the Hornady response. They may include some paperwork with their gauge but they didn't send me anything and I would like to see what they send out with the gauge.
     

    Deavis

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    Well, we can drag this out forever I guess but for rifles, a case gauge is not an ammo checker, if you note that the gauge does not even include the bullet. An ammo checker makes sure the case and bullet in a completed cartridge meet sammi specs. Do you have a rifle case gauge that actually encompasses the bullet in the case gauge? Pistol gauges do but I don't own a rifle gauge that does. Even Wilson (they invented the gauge) says " the cartridge case gage is not made to measure body diameters or neck diameters". That is why some ammo that fits a case gage fails the ammo checker. Ammo checkers check the entire cartridge (bullet and brass). This is all academic and many people are confused by it as well.
    I was not very happy with the Hornady response. They may include some paperwork with their gauge but they didn't send me anything and I would like to see what they send out with the gauge.

    Again, semantics by manufacturer vary but either it meets SAAMI ammo specs or chamber specs. It is one of the two. You dont have to encompass the bullet to meet the spec at the neck, you just need to encompass the neck. The leade is different, I'll grant you that, but that is rarely an issue except in very small cases that are the exception not the norm.

    Yes, I do have gages that fit the whole cartridge, we made our own blocks for that reason but after a lot of gaging we discovered that you can abstract the gage a bit and have the same result.
     

    rotor

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    The following video may do a better job explaining what I am talking about.



    I previously thought a rifle case gage would guarantee sammi specs too. I was wrong. Being able to make your own blocks is way beyond my ability. I just buy the gages. Of course, I may be wrong. I still haven't seen the Hornady unit so I don't know what that really is.
     
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