Significance of case gauge testing

[JimGun]

I recently purchased a Dillon Stainless Steel .45 case gauge. When testing some of my previously reloaded ammo, I found one round where the rim did not fit flush against the top of the gauge, as shown in the first photo. However, when plunk testing it in the barrel of my Kimber, see second photo, it looked just as well seated, as a round from a box of Winchester ball ammo, see third photo. I am not sure what the protruding rim is telling me or whether the round is safe to fire. I would appreciate any and all comments.

 

[entropy]

The gauge is probably tighter than your barrel. It should fire in your barrel, which you already tested it in, fine. I use the barrel from my 1911 as a gauge.

 

[ReloaderFred]

It's telling you that round won't fire in the gauge, but will fire in the barrel. Unless the gauge is cut with the same reamer as your chamber, all it will tell you is the round won't fit the gauge...........

Many reloaders get along just fine for years and years, and then they buy a case gauge and start doubting themselves. I'm not a fan of them, but others are going to tell you not to load without one. To each his own.. I've got them, but they just collect dust on the shelf above my bench.

Hope this helps.

Fred

 

[tcj]

I use a case gauge when I initially set-up my press for a caliber and then again only when I am loading ammo for competition as it is faster/easier than using my barrel. Also, for some calibers I have multiple firearms and so I know that if it passes the gauge it will run in all of them.

That being said, all of the ammo that gets relegated to practice instead of competition because it failed the gauge has always worked in my firearms.

 

[LiveLife]

As long as my Dillon 45ACP sizing die is set up properly (bottom of die barely kissing top of shell plate without daylight), I use the barrel with the tightest chamber as my gauge which is Sig 1911.

In comparison, Springfield & RIA 1911/M&P45 chambers are larger and PT145 chamber is even more generous.

 

[HOWARD J]

You shoot out of your gun barrel so I think you should follow what your barrel says.
loading 30 carbine I drop my cartridges into the revolver-spin it- no jambs I am good to go

 

[stoky]

Check for an extractor burr on the rim of the case, that keeps it from going fully into the gauge.

 

[macgrumpy]

Case gauges are made to help identify cases that wont match SAAMI standards but not all gauges check for the same features, some check lengths only while others check both lengths and diameters. If you build your ammo to fit your chamber then it'll work fine - in your chamber, but it might not work in any other chamber. I had a friend that built .45 ammo for me, it worked well in his .45 but jammed in mine. He eventually bought a case gauge and made the brass fit the gauge, it then fit my pistol and his.

 

[243winxb]

If larger then .476" in the web area, scrap it.

 

[jmorris]

The case gauge is telling you that there is a defect on the case that your barrel is not/cannot detect because it doesn't contact the defective location.

There is a chance the round will function just fine as well as a chance the defect could cause a malfunction because it hung up going into the breech face.

This is why folks shooting timed competition events use case gauges, not just barrels. Also why things like push through and roll sizers exist, because your dies cannot resize the rim or the defect would have been eliminated before you found it with the case gauge.

Put the round in the casegauge backwards and give it a twist, 9:1 it will drop in and out fine afterwards.

 

[rfwobbly]

The case gauge is most likely telling you that the extractor left a small ding on the rim which it doesn't like. Obviously, since the barrel doesn't envelope the entire cartridge rim, the barrel is simply not as picky.

This is not entirely not a bad thing. If you were a competition shooter and you were looking to improve your times, then the obvious thing is to only take your best ammo to the shoot. The case gauge, being more picky than your barrel, will cull out the not-so-good rounds.

Yes, the barrel is the ultimate judge, but if you are competition shooting, then you will quickly tire of dis-assembling your gun every time you need to reload. Much better to leave the gun, holster, and other range supplies in your range bag (ready to go) and the case gauge on the reloading bench (ready to help reload). Sure beats getting to the match without the slide on your pistol !!

 

[higgite]

Check for an extractor burr on the rim of the case, that keeps it from going fully into the gauge.

This ^^^. As an example, I loaded almost 300 rounds of 45Auto last week. about 20 of them wouldn't fit a Dillon gauge. Everyone of them had a burr on the rim and everyone of them fit the gauge perfectly after I filed the burr off.
Try to stick the cartridge in the gauge rim first. If it won't go in, there's no way the cartridge will pass the gauge test. But, if the culprit is an extractor burr, it will probably pass the plunk test using the barrel, just as you experienced.