Plunk test 9mm & .45 ACP in 1911

[Dylan O'Leary]

So I'm new at this, but I have a funny situation. The barrel of my 9mm 1911 (Springfield) passes the audio portion of the plunk test, even with rounds that are a little longer than SAAMI's max of 1.169". However, NONE of them spin in the chamber. That seems to be as critical a part of a plunk test than the nice sound of the case head hitting the case mouth firmly (correct terms?). Even an empty brass case won't spin. All of them sit under the hood/shroud, too, or right at it. A gunsmith said that I've probably got a particularly tight chamber at the case mouth (and I told him "Thanks, darlin'"). And that's why nothing will spin. Thoughts?

 

[BluesBrother]

Do you trust the gunsmith? If yes, problem solved. if not continue asking questions. The absolute test is if the cycling is flawless with your preferred ammo. No FE,FF,stove piping. Sounds like you're over-thinking this. The only thing my ex-wife said that I agreed with is "there is no perfection." And she probably heard it from someone else.

 

[ChrisC]

Audio test in plunk test? Thats a first I’ve heard that. Clean the chamber really well. Pay attention to the case mouth ledge where it can collect lead shavings. a properly SIZED brass should not have issue spinning. Keyword, sized properly. Fix the empty case issue first then move on the loaded rounds. Shorten OAL (within reason) until it spins freely. Also check your crimp. too much crimp can cause it as well

 

[Roaster's Gallery]

Definition of plunk

transitive verb
1: to pluck or hit so as to produce a quick, hollow, metallic, or harsh sound
2: to set down suddenly : PLUMP
intransitive verb
1: to make a plunking sound
2: to drop abruptly : DIVE
3: to come out in favor of someone or something : PLUMP —used with for
Other Words from plunkSynonymsExample SentencesLearn More about plunk

 

[ChrisC]

Thanks Jarvis!

 

[Dylan O'Leary]

>>Do you trust the gunsmith?
Yeah, he works at a very reputable gun shop locally, and probably the oldest, just north of P'cola.

>>If yes, problem solved. if not continue asking questions.
Well, I'm always gonna do that! But today I fried 50 of the longer rounds with only one problem (below), and already fire 200 of the same before. I'm pushing 124gr bullets at 1,500+fps so I wanna make sure I'm avoiding pressure spikes.

>>The absolute test is if the cycling is flawless with your preferred ammo.
So far so good except that I get light strikes on my primers (CCI 500 small mag). That might be an issue with the pistol (really new) or, of course, the 22lb spring and the high pressure I'm generating.

>>FE,FF,stove piping
Fail to Extract, Fail to Fire?

>>Sounds like you're over-thinking this.
My forte.

>>The only thing my ex-wife said that I agreed with is "there is no perfection."
One of the wives I dated (not my own) once said "Do you know what the enemy of perfect is? Better."

>>And she probably heard it from someone else.
You let her speak to other people?!?

 

[Dylan O'Leary]

Audio test in plunk test? Thats a first I’ve heard that. Clean the chamber really well. Pay attention to the case mouth ledge where it can collect lead shavings. a properly SIZED brass should not have issue spinning. Keyword, sized properly. Fix the empty case issue first then move on the loaded rounds. Shorten OAL (within reason) until it spins freely. Also check your crimp. too much crimp can cause it as well

>>Audio test in plunk test?
Audio portion --- the plunk noise. And, yes, I just made up the term.

>>Clean the chamber really well.
Done, every time.

>>Shorten OAL (within reason) until it spins freely.
Not even short Buffalo Bore rounds will spin.

>> Also check your crimp. too much crimp can cause it as well
I use a taper die (Hornady). And just now, following your leads, I took a brand new case (Starline) and put it in the taper die and pressed it, tapering it with no round in it. Still won't spin.

 

[ChrisC]

>> Also check your crimp. too much crimp can cause it as well
I use a taper die (Hornady). And just now, following your leads, I took a brand new case (Starline) and put it in the taper die and pressed it, tapering it with no round in it. Still won't spin.

What is this “taper die” you speak of? Is it a taper crimp die? Or a sizing die?

 

[Jester896]

this video shows an exaggerated image of over crimping....slight unnoticeable ones can also create an issue.



this case is a roll crimp type but I believe a similar issue can be created with a taper crimp.

 

[Snake-Eyes]

...
One of the wives I dated (not my own) once said "Do you know what the enemy of perfect is? Better."
...

You've dated multiple married women?


As for your 1911, if the rounds seat to the proper depth, then the light primer strikes shouldn't have anything to do with the chamber. With no fail-to-feed or fail-to-extract, it sounds like the chamber is fine. At this point, you could have a chamber within spec and STILL have pressure spikes if you seat your bullets too shallow and cause an OAL that effectively forces the rifling to seat/compress the round further once chambered.

 

[Dylan O'Leary]

>>What is this “taper die” you speak of? Is it a taper crimp die? Or a sizing die?
It's Hornady's Taper Crimp Seater Die.

 

[Dylan O'Leary]

>>You've dated multiple married women?
It's an old joke. The actress Zsa Zsa Gabor was married and divorced many times (slightly less than Elizabeth Taylor) and the story goes that Zsa Zsa was once asked, "How many husbands have you had?" and she replied, "What, of my own?" I laughed so loud when I first heard that.

>>As for your 1911, if the rounds seat to the proper depth, then the light primer strikes shouldn't have anything to do with the chamber.
I'm finding tiny specs of brass in the firing pin's house and even in the hole the pin goes through to hit the primer. I'm pretty sure it's left over from some Buffalo Bore ammo I used when i noticed the primers were hit very deep and shattered a bit. It's all cleaned out now. And I won't be using BB again.

Also, today, I took out the factory firing pin spring (Springfield) and put in one from Wolff that came complimentary with a 5-pack of recoil springs. Wolff's are 1/4" shorter and weaker (lighter) than the factory spring. I hope that lets the hammer's strike throw the firing pin forward with more momentum (less resistance). I'm even thinking about getting a steel pin or, if possible, one that has a slightly longer butt, like by 0.01".

Thanks again.

Hey, thanks everybody who's been replying --- and sorry I forgot to say as much in my replies.