Didn't Pass Plunk Test, But Load-Shoot-Eject OK

[boom boom]

The recoil spring is more than strong enough to push the bullet deeper into the case especially with a weak taper crimp. However, if you ride the recoil spring, you could have an out of battery experience depending on your firearm's safety mechanism. Whether the ensuing bullet setback is an issue depends on the powder, case capacity reduction, softness of the bullet, etc. which all affect pressure in the chamber.

I have had the same problem with Oregon Trail 124gr bullets with a tight chamber and short throated 9mm barrel (P6 Sig). Had a number of failures of the plunk test despite using a factory crimp die, proper OAL, etc. To remedy, I sorted the brass by headstamp which I normally do not do for handgun brass--using Remington 9mm brass instead of military or Winchester fixed most of my plunk problems with that particular bullet as the Remington was thinner at the end of the case. Eventually, I got a S&W 3rd Gen which had looser chambers and a longer throat which happily gobbled everything albeit at lesser accuracy. Put the Sig on a 124 gr. fmj diet and all was well.

 

[zeke]

Use to load low pressure lead 45 acp rounds to headspace off the bullet. in several specific instances, they were very accurate. Would not do this with a jacketed bullet.

Sometimes I shoot more than a couple hundred rounds through a pistol without cleaning. Function in a clean pistol may not be the same in a dirty pistol, especially if the bullet is being jammed into the rifling.

But as others have said, sometimes it works out.

 

[Potatohead]

What do you think is happening when you chamber them?

They're being squeezed way shorter I'm guessing you're saying? (maybe not, my brain is itsy bitsy compared to some of you guys)

Still, that would make mine way,way, shorter...

 

[gamestalker]

Just a thought here regarding gauges and how they relate to resizing, belling, crimping, and OAL. I realize the OP never mentioned anything about using a gauge, at least not that I recall. But I just wanted to assure the OP, that IMHO, using the chamber to determine proper fit, is the correct and most effective method, IME and opinion.

I've never owned or used a case gauge, I've always relied on the firearm chamber. I realize I haven't been reloading as long as some here, but I do have better than 30 years of experience, yet in all those years of never using a gauge, I've yet to have a problem related to fit and function. IMO, if it fits the chamber properly, nothing else needs to be done.

I'm not saying gauges are bad, not at all. But I don't personally think gauges represent our firearms, after all, we don't shoot the ammo through the gauge. Gauges represent an industry standard that's rarely, if in fact ever, the same dimensions of the firearm chamber. Some chambers are super tight, deep, shallow, or may have some other dimensional characteristic that contradicts what the gauge exhibits. Evidence of this is when we here of a reloader having an issue with cartridges that don't pass the gauge, however they fit and pass the chamber test with flying colors, which IMHO, this is all that matters. It's also come up that the cartridge will pass the gauge, but they won't pass the chamber check, which that right there should say something about the importance of using the chamber as the gauge.

As it is, reloading already comes with inherent risks, which is clearly pressure, lots of it. But if we consistently and diligently follow the proper methods, as have been established by the experts, we can minimize the risk to an acceptable level. In this thread the OP is already aware of the issue, as well as the risk associated with using the ammo in the short throat. So IMO, when a reloader recognizes the problem, they should do what we know to be the right thing. Other wise, we accept the avoidable known risk, and then hope we don't regret it. And depending on just how much more risk it represents, it's something I've accepted before, and I'm sure lots of others here have, but I would be reluctant to recommend that someone else do it. Now that I have that off my chest, the following are some options to consider that may minimize the risk of a pressure spike.

So, if it were me, and granted it's not, depending on how stout the current load is, I would proceed as follows.

Either seat the remaining rounds a tad deeper, just enough to minimize contact with the lands, but keep it under .010". This is especially important given this is a high pressure cartridge. As pointed out by someone else, contact with the lands is not going to be predictable, as to pressure spikes. Where as seating a little deeper and then monitoring the pressures, one would at least know what they will consistently have.
or
Shoot the remaining rounds through the firearms they passed the plunk in.
or
Sort, and use those that fit in the firearm that has the shallow throat.
and
In the future, make sure to seat the bullets so they pass the firearm with the shortest throat, that way they will fit properly in all your firearms, no more concerns about pressure spikes, thus future concerns will be significantly minimized.

GS

 

[nevadabob]

Thanks for the responses.

GS...no, I don't have a case gauge, have always relied upon the individual barrel chamber. I've fired off all the rounds made, that was before I posted. I bought a 100 bullet sample pack.

 

[tcoz]

Well that's why you visit THR. For the best advice.

+3....I found this out the hard way.

 

[jmorris]

I did not mention that I reloaded for more than a decade without owning a case gauge.

Only started using them when I started shooting competitively, where a malfunction could (did) cause a loss.

 

[Walkalong]

I never had a case gauge for pistol until I got a tight chambered EMP that locked up on some reloads. Reloads that ran 100% in other 9MM guns with more generous chambers. Probably close to two decades.

 

[nevadabob]

All is well...I'll be loading specifically for the PPX. I'll file this under what my Dad used to tell me as a kid when we were working on something out in the garage: "Rob, don't force it!". Thanks Dad!