Using a Case Gauge

[Phyffe]

So I just got a Shooter's box case gauge and started running my stockpiled ammo through it starting with my reloads and my carry ammo.

I noticed a lot of my reloads did not generally fail the parameters set by the case gauge, though my brand new ammo generally passes.

My question is though - SHOULD I BE USING THE CASE GAUGE AS IF I WERE DOING A PLUNK TEST ON MY BARREL?

Because if that were the case even some of my Federal HSTs do not drop in and out perfectly. Am I wrong in using it like that?

Would appreciate your thoughts!

[SI VIS PACEM PARRABELLUM]

I use the barrel from the pistol I have that shows the shortest throat which at this point is my 75BD. All my handloads drop right in that and drop right back out. As long as nothing sticks in that barrel I'm good to go. I started doing this years ago when first learned about the CZ barrel and it's short free bore and I've never had an issue doing it this way.
I have a 9mm case gauge sitting on the shelf collecting dust.

[JBruns]

I've found my S2O to be the pickiest gun I own on reloads. Since I shoot a lot, I needed something faster than 1 at a time tester. I bought the Hundo:
https://benstoegerproshop.com/100-hole-9mm-luger-hundo-chamber-checker-cartridge-case-gauge-anodized-black/

Works great. I'd say 8 out of 10 that are not flush in the checker will not subsequently work through the S2.

I also got tired of failures, so I swapped the 2nd station in my 1100 to the Lee undersized die. So the rounds are all sized twice now. It could be used for the primary sizing die too, of course. Very few failures anymore.
https://leeprecision.com/undersize-sizing-die-9mm.html

[SoCal]

I also got tired of failures, so I swapped the 2nd station in my 1100 to the Lee undersized die. So the rounds are all sized twice now. It could be used for the primary sizing die too, of course. Very few failures anymore.
https://leeprecision.com/undersize-sizing-die-9mm.html

I second that.

[Wobbly]

My question is though - SHOULD I BE USING THE CASE GAUGE AS IF I WERE DOING A PLUNK TEST ON MY BARREL?

No. And here's why...

You specifically stated the "plunk test", AKA the "plunk and spin" and other similar names. The most important part of the test is to check the bullet-to-rifling clearance to insure no OOB firings. Since the gauges do not have any rifling, they cannot check this critical clearance. You will always need your barrel for that test. This is why we tell you to take your barrel with you when you are ammo shopping.

Now, IF you've already checked your OAL and 1) you know that there is no rifling contact, and 2) you know your OAL variations are being kept to a minimum.... THEN you can use your cartridge gauge to check roundness, concentricity, taper crimp and look for extractor burrs on the cartridges as they come off the press. But that is not what you specifically asked about.


Placing too much trust in the cartridge gauge is how people end up getting hurt with OOB firings/ explosions. Cartridge gauges are extremely helpful devices. I own one for every pistol caliber I reload. But you must understand that they have limits, and you must respect those limits.

 

[rg422]

I, too, use the Hundo 100 round case gauge. It’s a great tool to have. I no longer shoot any reloads unless it’s passed through the case gauge. It’s isolated reloads with split cases a few times. (I load range pick up brass). I’m sure using your barrel as the case gauge would be optimal, but for me that’s just going to take too long.

[flatsixfan]

Once I determined my optimum OAL via the plunk test, I set up the Dillon RL1100 with Redding Pro Competition dies.  Using same headstamp brass with Zero JHP bullets, I do the final checks using the Armanov Checker Bundle.  Checking 100 at a time, I can easily check for non-spec rounds, check primer appearance and approximate depths; then using the OAL Round Uniformer and a straight edge, I can easily look for any rounds that may be below or above my specific OAL range.


https://usa-shop.armanov.com/products/case-gauge-bundle-3-in-1

In over 5k match reloads, have not had the first failure to fire or function!

Highly recommended!

[tdogg]

I have found that the case gauge (I use a Hundo) is much tighter than any of my CZ barrels.  As Wobbly stated it doesn't check OAL issues but will tell you if you have a case issue (bulge, crimp, case length, etc...).  I have a fine tuned my process to eliminate most case issues but I still have the occasional failure.  I'd say that >99% will "plunk" into the case gauge, the rest I just have to discern if the failure warrants a segregating it for practice.  My general rule is to just pull it for practice.  I roll size and use a lee undersize die (even though rollsizer doesn't recommend using the undersize die) and I still have an occasional failure.  I actually have pistol cases that end up too long after my process and it shows on the Hundo case gauge (hence probably the reason for not using the Lee undersize die).

If you are having a ton of case gauge failures, then you probably should look at your process.  I had alignment issues during seating that required adjusting my press timing.  If you running lead/coated lead that adds a complicating factor using a case gauge.  Generally oversize bullets will not pass as easily as well.

Cheers,
Toby