9mm round fails the plunk test but works in the barrel

[Certaindeaf]

I didn't say anything about a gauge, I simply stated just because the slide closes and goes bang doesn't necessarily mean "You're golden".

True. A case gauge or the plunk tests/proves that it will chamber, not verify the powder charge, show an obstruction in the barrel, defect in the gun that will allow or cause an out of battery discharge or a high primer that could slam fire.

 

[Capn Jack]

I don't own any handguns where the case isn't fully supported when the slide, or cylinder is closed so I'm having trouble relating to your problem. I do use chamber gauges on all of my reloaded rounds, (Rifle & Pistol) after sizing and after seating the bullet.

 

[RedRob]

I run every round that goes into a semi-auto thru a case gauge. 223 that fail is usually 2-3 per thousand. Those get pulled. Pistol ammo I'll pull my barrel and check it in a couple if it drops in I go ahead and put it in one of the spare mags for that gun. A lot of pistol chambers are .001-.003 larger than a case gauge. Hence a fired piece of brass will chamber in you pistol but won't fit in the gauge. When I say chamber it might or might not drop in but drop the slide on it and it will chamber and will pull back out with the extractor. In that I guess you could get it all the way in a case gauge but then you would have to punch it out. If it's the right caliber the right charge and it drops in the chamber you're good to go.
The only reason I pull the 223 I have this bad habit that I get some wolf steel case or some dirty shooting ammo and end up using the forward assist. Good thing for a dirty gun bad thing for a cartridge that didn't get sized properly.

 

[Camelfilter]

Pardon my ignorance, 'case gauge'?

Like such & similar.

Can get singles, as well as larger blocks. Various manufacturers, in many calibers.

Can also get several calibers in a single block, I believe.

 

[RedRob]

Like such & similar.
View attachment 841822
Can get singles, as well as larger blocks. Various manufacturers, in many calibers.

Can also get several calibers in a single block, I believe.

That's what it is. I prefer the singles. I just find it easier. I can grab a round drop it in touch across the top and twist hand to dump in a bucket while grabbing the next round. Takes 2-3 seconds a round. All while vegging out in front of the TV.

 

[arakboss]

I was under the impression barrel chambers were often manufactured looser then case gauge specs?

 

[LSWC]

I've ran into rounds that would fit in one case gauge and not another - both gauges or ammo checkers were manufactured by the same company.
One was bored slightly smaller than the other.

Rounds that I flagged did chamber and fire fine.

I test all my rounds and of the small percentage that do fail there is usually an issue vs a corner-case tolerance issue.
Gauges and ammo checkers are good tools but they're not perfect. Some interpretation and inspection of failing rounds should be expected.
Worst case and erring on the side of caution, pull the projectile, primer and powder and scrap the brass.

 

[Member 5605]

You can fail a gauge test because of a boogered rim...


Just saying.

 

[Mikej]

I was under the impression barrel chambers were often manufactured looser then case gauge specs?

It seems so, doesn't it? 9mm is kind of a weird round to load because the case of 9mm has the slightest taper. When sizing you have to be making the case the slightest bit smaller diameter toward the base. When I load 9mm, using a Lee die set, there is always a slight bulge in the brass where the base of the bullet is. In this case (no pun intended) it's possible in the seating crimping stage you are over crimping a little and making that slight bulge where the base of the bullet is, a couple thousandths larger. Try backing off on the crimp until you only feel a slight resistance at the bottom of the stroke.

 

[Ironbar]

**UPDATE**

Problem solved. I was misreading my calipers. I simply didn't have the bullet seated far enough. It drops in the case guage just fine now.

I've been taking the setup on my new Dillon very slowly making sure to check and recheck prior to actually turning out rounds.

I now have the seating die and factory crimp die set exactly to spec.

Next step will be to dial in the powder charge and the RCBS Lock Out die and then I'll be making ammo!

 

[ageingstudent]

2 examples of the finest finished case gauges money can buy. .40 cal single hole and .357 5 hole. You can't beat making ammo to your own chamber.




Here's the deal for you folks new to reloading...a case gauge like those pictured in previous posts is built to make sure that a round will fit in any SAAMI (or possibly CIP) firearm of that caliber. The tolerances on that case gauge are tight, and rightly so, because from the guage it needs to fit and fire in a great deal of firearms in .xx caliber. Kinda like factory ammo which most of us handloaders are kinda less than impressed with. It shoots so so usually. It's one size fits all for a particular caliber.

I have an extreme but great example of this. I have a fairly rare .351 winchester and the chamber is loose. Real .351 brass splits from mouth to base every time I shoot it. If I had a .351 gauge it wouldn't make a bit of difference. If I had a real .351 die that wouldn't help either they are much tighter than my chamber. So I use a .357 mag die with .357 brass and it's a miracle I don't get split cases. I check them in the chamber they are going to be fired in. I'd be willing to bet those cases wouldn't fit in a .351 gauge.

The takeaway is that if you are loading for several guns a gauge might be useful; however, I load for 5 different .38s and don't have a case gauge. My M36 has the tightest chambers and if they fit in that one they will fit in the others. My M36 is my defacto case gauge in that caliber.

YMMV but I haven't seen the need for the extra expense of a gauge. Although they look kinda cool I wouldn't mind having one for eye candy on the bench. Just a considered opinion based on my experience. Not busting on anyone.