Plunk test

It is a simple and Valid test .
It shows me my seating depth , especially with cast bullet handgun loads , are seated deep enough to not get caught by the barrels throat/rifling .
When a bullet is jammed into the throat ... it can be a Bear to get unstuck and sometimes extraction will remove a case but leave a bullet lodged in the throat .
The plunk test shows me the round will drop in freely and more importantly ...
... drop out freely .
Your barrel is The Best gauge to use ... trust me on this one !
Gary
 
I once read there is "Reloading" and there is "Handloading"
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The problem with that is that any honest definition covers both. Unless the "reloader" is using powered equipment, they are doing it by hand, and that makes them a handloader. And the "handloader" (unless only using virgin brass each time) is reloading ammunition, and that makes them a "reloader".

And no matter which name you choose to use, there is a range of care taken that goes from "finding the absolute best" (of whatever you're after) to "works well enough" for whatever you need the round to do.

One loader can load ammo either way, or both ways, or somewhere in between.

Part of that depends on what you are shooting. The steps done by match shooter and serious varmint hunters with their tuned rifles, to make the best ammo they can, to win a match or zap small varmints at long range are seldom any use in an old deer rife which was never made for more than "minute of deer" to begin with.

Different strokes for different folks, but also different levels of effort for different things in the same folks. I am a handloader who reloads. TO me, the only difference between the two words is the spelling. ;)
 
I’m not sure we are all getting what the “plunk” test is and why use it. You drop the round in and the headspace feature, the mouth of an auto round. Hits the end of the chamber. You shorten the round until the bullet doesn’t touch the rifling. This ensures that an auto pistol round does not hang up in the rifling when fed. If it sticks, you can pull the case off the bullet and jam up the whole gun.

Is it the most accurate oal, probably not. Does it prove the round will feed, no. Is it required, no. If you go longer, it will be ok, up to the point that you stick a bullet and the pistol is inoperable. If you go shorter, it too will be ok, until it is short enough to change the pressure to an unsafe level. So why do it?

Because the most important thing in setting oal is to find the max oal that will not stick a bullet. From there, shortening may solve a feeding issue, but not usually.

This is not a case gage replacement, nor is a case gage a plunk test replacement. You need both, or you can reject both. It is your choice. A case gage is to determine mostly if the round fits in a minimum spec chamber. That’s all. I like to know that. Others scoff. Which of us is clearing a practice round mid drill?
 
I learned to use the plunk test for reasons nobody mentioned here; which seems kinda odd to me (or maybe I was just totally missing the point?). I have quite a few earlier glock barrels which are notorious for the infamous "Glock smile" which was a result of the feed ramp being machined into and past the chamber face resulting in potential lack of support of the case head around or just past the web. I found this was more of a case diameter thing (like bullets swelling the case diameter on seating rather than an absolute headspace thing) so when doing the drop test I looked for the thunk which was "proof positive" the case wasn't hanging on the chamber wall while verifying the the where the case rim groove meets the case wall was more or less flush with the chamber face. Eventually became habit for all my semi auto pistol reloads. Am I off-base here?:confused:
 
But beware of exceptions. My earlier description of the 1911 is an example, though other designs and older guns, in particular, can have the same issue. The barrel makers all chamber their barrels to SAAMI spec but have no control over how tightly the barrel extension and link lugs will fit an individual gun, so they have to do some compromising that can and does result in excess headspace in some guns. Even match barrels, where you file the barrel extension to fit, have an unknown exact headspace if you don't wait to final ream the chamber after all the other fitting is done. As a result, I saw one estimate 20 years or so back that up to 70% of out-of-the-box non-match grade 1911s were actually headspacing on their extractor hooks instead of the cartridge going into the chamber far enough to "plunk." In other words, excess headspace was the rule rather than the exception. This is where handloading to customize COL for the best function and performance in the individual gun can produce serious precision improvements on the target.

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At the last NRA Annual Meeting gun show, one manufacturer told me everything now is being made by CNC gear, so the looseness we used to have to learn how to fit up is dying out. I haven't shopped for new 1911s for decades now, so I'll have to take a tour of the local gun shops and see what I can discern about the state of the art. Meanwhile, you can't be sure the SAAMI spec indications of a cartridge gauge will be applicable to your gun until you prove it.
 
Nathan said:
I’m not sure we are all getting what the “plunk” test is and why use it. You drop the round in and the headspace feature, the mouth of an auto round. Hits the end of the chamber. You shorten the round until the bullet doesn’t touch the rifling. This ensures that an auto pistol round does not hang up in the rifling when fed. If it sticks, you can pull the case off the bullet and jam up the whole gun.
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I disagree with your description. The plunk test is used in auto pistol barrels making sure the round chambers so that the base is even with or shorter than the hood. That's it. That insures that if it feeds it will go into battery. It also proves that your ammo is not oversize when compared to the chamber.

Furthermore I agree with @Unclenick in his description of typical straight wall pistol cartridge headspace. Although the spec is for headspace on the case mouth that almost never happens as straight wall cartridges shorten with each firing.

For .45 ACP I use a new barrel to check reloads. I have found that the chamber in the new barrel is at least as tight as my pistols. If the reloads drop into the new chamber then they will fit in my pistols. Feeding is a different issue and I am lucky in that both bullet profiles that I use (lead SWC) run in both guns I currently have. I have previously had guns that just would not feed one or the other of the two I use. I could maybe improve accuracy by loading for each individual pistol but I don't allocate the time for that.
 
I think Nathan and Black Walnut are saying the same thing.

Here’s another way to look at it:

If you “plunk” a finished cartridge and the base of the case is even with the hood of the barrel, the case has headspaced properly on the mouth of the case and the bullet is not engaged in the rifling.

If the cartridge is too high, either the case is too long or the bullet is not seated deeply enough and has engaged the rifling. If you know your case lengths fall between the SAAMI maximum and “trim to” measurements, then the seating depth of the bullet is the problem.

As Black Walnut pointed out, generally the cases shorten when fired, but I’m not certain that is an issue because I have noticed resizing the case lengthens it again. At least in the 9mm cases I have measured before and after resizing, and I have never resized a case where it is longer than the maximum 0.754”.

If the cartridge “plunks” too deeply, the case is too short and the headspace is insufficient. It can’t be a bullet seating depth problem.
But I have to wonder how commonly this occurs unless one trims the case too short.

One other possibility is also virtually impossible. The case is too short but the bullet is seated far enough out and into the rifling that the “plunk” test has the case exactly even with the hood. Again, are short cases common?
 
I disagree with your description. The plunk test is used in auto pistol barrels making sure the round chambers so that the base is even with or shorter than the hood. That's it. That insures that if it feeds it will go into battery. It also proves that your ammo is not oversize when compared to the chamber.

Furthermore I agree with @Unclenick in his description of typical straight wall pistol cartridge headspace. Although the spec is for headspace on the case mouth that almost never happens as straight wall cartridges shorten with each firing.

For .45 ACP I use a new barrel to check reloads. I have found that the chamber in the new barrel is at least as tight as my pistols. If the reloads drop into the new chamber then they will fit in my pistols. Feeding is a different issue and I am lucky in that both bullet profiles that I use (lead SWC) run in both guns I currently have. I have previously had guns that just would not feed one or the other of the two I use. I could maybe improve accuracy by loading for each individual pistol but I don't allocate the time for that.
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First, I appreciate your disagreement.

Is base to hood a known dimension? What is it related to? Generally the hood is hard fit to the breech face or it appears so, but in reality, there is always a slight breech face to hood gap(not visible because gap is forced to the barrel lug end) and still have a functioning gun. I think we never see it because the spring closes that gap and most auto cases are short. With a long case, and poor lug to breech length, you could have a gap on an in spec gun/ammo, I believe. Not normal, I agree.

If you “plunk” a finished cartridge and the base of the case is even with the hood of the barrel, the case has headspaced properly on the mouth of the case and the bullet is not engaged in the rifling.
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Sort of…with a proper plunk, you hear the case hit the chamber. If the bullet hits the lands, there is no plunk sound. Also, when flipped over, it should fall out without holding the lands at all. Too long, the bullet hangs up on the lands. Too short….well, it won’t tell you that. Case too long, it sort of shows this, but that is more of a gross check….like it is 0.01” too long and you spot it above the hood. Maybe the case is too long, maybe hood too short. Regardless 0.01” is a mile. Case length is a caliper check.
 
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In auto pistols, the usual clanger is the chamber throat/leade and bullet ogives. Seems like the gunmakers usually do OK on the chamber - unless you fall into the Minimum Match Chamber trap - but throats are rather variable. And there is no spec for bullet noses at all. I can tell a difference from gun to gun but it seldom affects the load. Seldom not never, I have one lot of ammo that I will have to shoot in one particular gun.

Back in the previous century, when cast semiwadcutters were usual fare for .45 ACPs, we commonly loaded them to "headspace" on the shoulder of the bullet, seating so that a plunk left the case head even with the barrel hood. Case length and extractor engagement were not a factor.
 
Considering the barrel to slide locking lug contact, should the hood be hard fitted to contact the breech face at full battery?
 
( there is "Reloading" and there is "Handloading" )

well i am a handloader, and seeing that i have never baught any empty brass; that makes all my handloads, reloads.

but yeah to the origenal question, i load mostly bottleneck rifle cartridges, and the "PLUNK" test does what it does, it tells me if the cartridge will chamber or balk before it gets there. so i use the plunk test every time i change the specs on any load.

so yeah.
 
Jim Watson said:
Back in the previous century, when cast semiwadcutters were usual fare for .45 ACPs, we commonly loaded them to "headspace" on the shoulder of the bullet, seating so that a plunk left the case head even with the barrel hood. Case length and extractor engagement were not a factor.
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Presactly!


HiBC said:
Considering the barrel to slide locking lug contact, should the hood be hard fitted to contact the breech face at full battery?
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The slide usually pushes on the hood (aka, barrel extension) to make the barrel slide up into battery, so contact is made.
 
In contrast to rifle handloading, I gather little attention is paid to the distance a handgun bullet has to jump to engage the rifling as a method to determine accuracy. Maybe the usual target distance of 15 yards or less is a factor, leaving us with no more than a concern that the seating depth should not be long enough to prevent proper battery engagement nor too short to create dangerous pressure situations.

I suspect that I’m not alone when I look for a recipe that utilizes a 115gr bullet for my 9mm and I follow the directions that include the OAL of the finished cartridge, and assume that OAL will be safe in my pistol as long as the “plunk” test is passed. Is it really that simple?

But this does raise a question as to how the various reloading handbooks establish the recommended OAL in the various recipes. What follows is an example of the advice often given by 44AMP that various methods and advice need to be used with caution because the gun in the handbook is not necessarily going to work in YOUR gun.

Here are recipes for 9mm 115gr bullets from the various handbooks I’ve accumulated.

The Lyman 50th Ed. lists a Hornady 115gr HP/XTP having an OAL of 1.090.” I’ve loaded that without even considering that they didn’t use a Walther PPQ.

So I checked a few others, and NONE of them used the same pistol that I have:

Hodgdon #27: SPR GDHP 115gr OAl 1.125”

Speer #12: SPR GDHP 1.125” – TMJ 1.135” – JHP 1.125”

Hornady 4th Ed – (differs from Lyman) 115gr HP/XTP OAL 1.050” – FMJRN 1.105”

Nosler #3: lists loads for 90gr and 115gr unnamed bullets and gives the same OAL of 1.100” for both bullets.

Now here’s something that makes it even more complex. I have a box of Factory LAX 115gr RN with an OAL of 1.150” – and I have a bottle of the same 115gr X-Treme bullets. The bullet itself has a base-to-tip measurement of 0.552”. Using a .35 caliber comparator, I measured the base to “ogive” as 0.232”.

I have Precision Delta 115gr HP that has an OAL of 0.551” and the base-to-ogive is 0.273”.

I have Everglades 115gr HP that has an OAL of 0.558” and a base-to-ogive of 0.242”.

If I load all of these to the same OAL length, is it reasonable to assume they will not be equally accurate simply because the bullet jumps will differ?

Well, I just arbitrarily chose to mimic the LAX measurement for my X-treme bullets and I made 10 rounds at 1.150”. Then I made 10 P.Delta rounds at 1.100” and 10 of the Everglades at 1.125.” They all passed the “plunk test.

I fired them at 15 yards from the bench at a 6-inch white paper plate with a 4-inch green dot.

Evergreen was the winner with a 2.25” group with all 10 shots in the green dot.
Precision Delta put 5 in the green, 4 in the surrounding white plate and 1 was a complete miss.
X-treme put 7 of the 10 in the green and 3 in the white plate.

I wondered if the space for the powder plays a significant role. I did a few calculations and determined the Everglades load had 0.569” of powder space. The X-treme was 0.598” and the P. Delta was 0.549.” My next experiment will be to make the OALs whatever it takes to leave the same powder space under each bullet. Stay tuned.
 
cdoc42 said:
If I load all of these to the same OAL length, is it reasonable to assume they will not be equally accurate simply because the bullet jumps will differ?

Well, I just arbitrarily chose to mimic the LAX measurement for my X-treme bullets and I made 10 rounds at 1.150”. Then I made 10 P.Delta rounds at 1.100” and 10 of the Everglades at 1.125.” They all passed the “plunk test.

I fired them at 15 yards from the bench at a 6-inch white paper plate with a 4-inch green dot.

Evergreen was the winner with a 2.25” group with all 10 shots in the green dot.
Precision Delta put 5 in the green, 4 in the surrounding white plate and 1 was a complete miss.
X-treme put 7 of the 10 in the green and 3 in the white plate.
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Accuracy testing is at best, not always reliable. You can get very different 10-shot group sizes even when using the exact same ammo. Below is an article that looks at this issue.

https://www.ssusa.org/content/accuracy-testing-how-many-shots-in-the-group/
 
Near the end of that link, the author said:

"Fifty-shot groups seem like they should be more than enough to tell you how your gun likes the ammunition, but we learned that even 50-shot groups with the same ammo can be different sizes."

So I can't fly like a bird unless I am a bird, and even then, birds fly differently?

From a rifle history, I can say I may not be able to get a 0.7-inch group with 5 shots from my 6mm PPC every time I go to the range, but it invariably beats the 1.0-inch group that I just as often get with my 6.5mm Creedmoor.

Regarding the experiment I described, if the Everglade bullets provide a better group, size notwithstanding, than P. Delta and X-treme, the size doesn't matter.
 
In contrast to rifle handloading, I gather little attention is paid to the distance a handgun bullet has to jump to engage the rifling as a method to determine accuracy.
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Bullet jump to the lands is one factor that can affect accuracy. Its a big deal (to some people) shooting rifles, but that's because rifles, generally, have fewer factors involved, or those factors have a lesser effect, simply because of the way the rifle is made.

First off, many semi auto pistols have barrels that move, in relation to the sights. That single factor can be more dominant for accuracy than bullet jump to the lands is.

And, you can't exactly do the rifle shooter's "chasing the lands" if you're shooting a revolver.

Also, things that are not the ammunition affect the "shootability" of handguns compared to rifles, and have an effect on the accuracy when the gun is fired by a human being.

The industry standard maximum loaded length for the 9mm Luger round is 1.169". That is from cartridge base to bullet tip. This number is derived from the original loadings (which were the only loadings commercially available for nearly 3/4 of a century) which used a fairly long nosed, fairly pointed FMJ RN.

Consider this, when dealing with bullets of equal weight, the hollow point is going to be shorter than the RN. When seated with the same amount of bullet in the case the HP will have a shorter overall loaded length. And lighter bullets are going to be shorter still.

I fired them at 15 yards from the bench at a 6-inch white paper plate with a 4-inch green dot....

Precision Delta put 5 in the green, 4 in the surrounding white plate and 1 was a complete miss.
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You missed a 6" plate at 15 yards, firing from a bench, and it's the bullet's fault?? IF that's the cause, you need better bullets. ;)
 
44amp; admittedly i am not a pistole kind of guy, but did i understand correctly "of the same weight a hollow point bullet will be shorter than a round nose" ?

it may be general design normal, but it sounds counter intuitive. are they generally designed that way "shorter + fatter" ?
 
georgehwbush said:
44amp; admittedly i am not a pistole kind of guy, but did i understand correctly "of the same weight a hollow point bullet will be shorter than a round nose" ?
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44AMP is correct, with the only caveat being they are both from the same manufacturer.
 
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