Case Gauges?

[alamo5000]

I am thinking about getting a case gauge specifically for 300 Blackout.

Here is the basic background which hopefully will help you understand my intentions.

Quite a while ago I loaded up some 300Black but one of the cases the neck was a tiny bit too thick. It was a "converted case" which it went almost all the way into battery before detonation. The end result was a kaboom that caused a bit of damage.

As for reloading though I am like a butterfly going cartridge to cartridge. Now that I'm considering loading more Blackout ammo I want a way to test it other than having an explosion a few inches from my face.

I have never really used a case gauge before so I'm not that familiar with which one people like or even if it matters.

The entire purpose is unique to 300BLK simply because I have a lot of converted brass laying around that will eventually be loaded up.

Are there any specific brands or designs that you like better than others? If so, why?

And in your opinion would a tool like that actually help detect cases that might have slipped through the cracks?

 

[Hoser]

US headstamp is normally ok. When you get into offshore brass its a crapshoot.

I usually recommend Lake City and Winchester. Those are two known good to convert brass.

Radway Green is 100% a no-go.

 

[waspocrew]

Follow this list for headstamps worth converting:

STICKY - Good/Bad brass list converting 5.56->300blk » 300BlkTalk

For a case gauge, I’d recommend a Sheridan gauge. You can have a standard or one with a cut out so you can see where things are contacting.

300 Blackout Ammunition Gauge

We had an issue with production before the holiday closure, these will be back in stock by Jan 8 Choose between SLOTTED or NON-SLOTTED. AMMUNITION GAUGES are uniquely designed to check loaded ammunition, giving you the ability to check your factory ammunition or reloads against…

sheridanengineering.com

 

[alamo5000]

Yeah, I found a specific list of which brass works/doesn't. I will not be converting any more any time soon though. I probably have a 5 year supply or more than that even.

I still have a bunch of the older brass that's already been done.

 

[bax]

I've had good luck with Wilson

 

[alamo5000]

I have been looking online and those slotted case gauges are really expensive but they seem to have the most useful design.

Instead of just "it doesn't fit" you can see what doesn't fit.

Of course I'm not trying to load up some super secret precision 300 BLACK. I am really just doing it as a extra safety precaution.

That said, in other calibers I wonder how useful these would be in say a load development context?

 

[Hawk in WY]

I have a few.

I use them to confirm sizing is adequate although the Hornady gauge is better for shouldered rifle rounds and the plunk test for pistol barrels is as good.

If I needed assurance that each and every round would chamber, I would drop each one in the case gauge. I almost never do that.

So somewhat useful but there are other options.

 

[HemiPowrd]

I'd highly recommend the Sheridan Engineering slotted case gauge. It's helped me solve a couple of case sizing issues before a kaboom.

 

[Molon]

I've had good luck with Wilson

That is not a case gage and it specifically will not address the OP's concerns of case neck thickness.

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[alamo5000]

That is not a case gage and it specifically will not address the OP's concerns of case neck thickness.

....

This is the first and foremost thing driving me to purchase a new tool. With any other cartridge I don't have the same fears.

I ended up getting an RCBS tool for the Blackout issue. I chose that one because it seems like it will resist corrosion more because of the coating on it.

All I am doing with Blackout is making sure I don't get another bad boom.

While I was looking at these things I did a impulse buy of an LE Wilson gauge for 6 ARC. Plus it gave me free shipping on my entire order because it pushed me just over the free shipping limit.

When I read the description of the LE Wilson tool it says it's for measuring head space. Basically you can put a fired case in there and measure it so you can determine how much to size your brass.

That particular tool to me would be a lot less useful for the Blackout but it could be extremely valuable for the 6ARC.

If I find it is useful I might order others. If the RCBS doesn't do what I like it's only $20.

 

[Hoser]

Case/chamber gauge vs headspace gauge.

Big difference.

 

[bax]

Case/chamber gauge vs headspace gauge.

Big difference.

OP had a boom. He says because a case neck was too thick, weapon didn't go fully into battery. If I understood correctly, bullet diameter plus neck walls were a tight or interference fit in his chamber, bolt did not completely engage locking lugs, and bad things happened.

My Wilson 308 case gauge is chamber-sized including the neck. A sized round drops in. An unsized case has an interference fit in the neck. That is, the case neck is snug and the case has to be pushed into the gauge with light finger pressure. I inserted my SAAMI 308 chamber reamer into the the Wilson gauge, seems like a perfect fit to me.

If Alamo5000 has a SAAMI chamber, a Wilson gauge, and a loaded round and the loaded round does not drop into the gauge, why is that not the message he is looking for?

How is a case/chamber gauge different that that?

 

[Highbrass]

I had issues with neck thickness on my converted brass. My solution was an inside reamer for my RCBS trim pro. Along with a Lee factory crimp die seemed to solve most of my issues. I still gauge rach round.

 

[HemiPowrd]

OP had a boom. He says because a case neck was too thick, weapon didn't go fully into battery. If I understood correctly, bullet diameter plus neck walls were a tight or interference fit in his chamber, bolt did not completely engage locking lugs, and bad things happened.

My Wilson 308 case gauge is chamber-sized including the neck. A sized round drops in. An unsized case has an interference fit in the neck. That is, the case neck is snug and the case has to be pushed into the gauge with light finger pressure. I inserted my SAAMI 308 chamber reamer into the the Wilson gauge, seems like a perfect fit to me.

If Alamo5000 has a SAAMI chamber, a Wilson gauge, and a loaded round and the loaded round does not drop into the gauge, why is that not the message he is looking for?

How is a case/chamber gauge different that that?

I'm not an expert on this, but I do know the Sheridan Case Gauge is cut to minimum SAAMI chamber specs so unless your chamber is smaller than SAAMI spec then if it fits the case gauge it should fit in your chamber. I've used other go / no go gauges, but they aren't all cut to minimum spec so don't always tell the whole story. With the Sheridan gauge I know if it fits in the gauge it'll fit in my chamber. I check every round to avoid problems.

 

[Molon]

If Alamo5000 has a SAAMI chamber, a Wilson gauge, and a loaded round and the loaded round does not drop into the gauge, why is that not the message he is looking for?

The LE. Wilson gauge from the link posted above is a headspace gauge, not a minimum SAAMI spec chamber gauge. The headspace gauge has larger body diameters to allow a fired case to be inserted into it. The pic below shows an LE. Wilson headspace gauge on the left and an LE. Wilson minimum SAAMI spec chamber gauge on the right.

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[Molon]

When I read the description of the LE Wilson tool it says it's for measuring head space. Basically you can put a fired case in there and measure it so you can determine how much to size your brass.

If you’re going to use the L.E. Wilson headspace gauge for comparing the headspace of fired cases to resized cases, you should be using the L.E. Wilson micrometer top with it (shown on the right in the picture below).

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[alamo5000]

The LE. Wilson gauge from the link posted above is a headspace gauge, not a minimum SAAMI spec chamber gauge. The headspace gauge has larger body diameters to allow a fired case to be inserted into it. The pic below shows an LE. Wilson headspace gauge on the left and an LE. Wilson minimum SAAMI spec chamber gauge on the right.

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I bought two different ones. One for Blackout and another for 6 ARC. The 6ARC one is the one on the left in your picture.

In Blackout I'm simply trying to avoid another problem from ammo not chambering.

6 ARC is an entirely different thing. I am trying to get very precise ammo in that cartridge, hence the two different gauges for two different purposes.

 

[Sniff]

I have, and love, the Sheridan slotted gauge.

All my Blackout brass is converted by myself from various .223 / 5.56 cases. If there's an issue with the case, or the loaded round, I can see what it is instantly

 

[bax]

The LE. Wilson gauge from the link posted above is a headspace gauge, not a minimum SAAMI spec chamber gauge. The headspace gauge has larger body diameters to allow a fired case to be inserted into it. The pic below shows an LE. Wilson headspace gauge on the left and an LE. Wilson minimum SAAMI spec chamber gauge on the right.

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Yup, you're right. I went back to the instructions and what you are describing is what they built it for. The minimum chamber gauge would be the correct Wilson tool.

The only time I used brass where the headstamp was different from the caliber was Lapua 220 Russian neck-expanded to 6 PPC. That process makes the neck a little thinner. After expanding I had to turn necks down to .008 thickness in order to fit a .261-neck chamber. The gunsmith who chambered-and-fit my barrels made a gauge from a piece of barrel and the same chamber reamer used to cut the chamber. As purchased, 220 Russian brass (neck OD around .248) fit loosely into the gauge. Necked up brass (neck OD around .267) would not fit into the gauge. Neck-turned brass (OD around .255) and loaded rounds (OD around .259) would fit. I still have those gauges.

In the case of my 308 Wilson case gauge (bought about 25 years ago), the gauge neck portion is approximately the same as my SAAMI chamber (I guess that it is within half a thou) so it would work for the issue that Alamo described but it is the wrong tool for the problem.

 

[alamo5000]

If you’re going to use the L.E. Wilson headspace gauge for comparing the headspace of fired cases to resized cases, you should be using the L.E. Wilson micrometer top with it (shown on the right in the picture below).

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I went ahead and bought that micrometer as well as an identical gauge, but for 223. I figured it could come in very useful, and more than anything the ease of use is definitely a thing.