9mm plunk test

[Russman]

So I have reloaded 38 and 357 with no problems.Now I am reloading 9mm.i have a 102 gr 1r bullet from lee.They say the oal should be1.030,but I have learned from this site to just go to the crimp groove.My question is when I do the plunk test my cases are sticking out a bit further than with factory ammo.Is this dangerous?I have the bullet sized to 358, could that be my problem?

[NSB]

If they don't fit the "plunk" test/gage, you're probably going to have feeding or ignition problems. OAL isn't all that important if the loaded round does fit the plunk test/gage. The bullets nose/ogive determines length more so than what the book says. If it fits, it's probably just fine. No, it's not dangerous being just a bit long. Crimp groove really isn't an issue, you should be using a taper crimp on this round rather than a roll crimp to begin with. I've used lead bullets sized .358" in a couple of different semi autos with no problems, but they weren't anywhere near max loads either. If you don't have an actual gage to use for the test, get one. They're very useful when you're trying different bullets for your gun.

[Dusty Bannister]

He already has a gauge. That is the barrel from his firearm when dismounted from the slide. More accurate to use that gauge than something made to a minimum/maximum specification. The actual barrel takes into account any individual features such as bore/groove, depth of lands, angle of throat, and of course the depth of the chamber or any free bore present.

[Conditor22]

If the cartridge is sticking out of the barrel in the plunk test and the factory ammo is not then you need to seat the boolit deeper.

Another way to test is Load a cartridge with no primer or powder then see if the gun will go into battery ie slide fully closed and ready to fire, if not the boolit is seated too deep.


** the 9MM has a tapered case, don't crimp it too much or you'll downsize the boolit and get leading/poor results. Pull a boolit with a hammer type puller and make sure you are not downsizing the boolit

[JBinMN]

Others posted before I was done typing, but I am posting anyway in order to try to help...

That groove in that boolit is the lube groove & not a crimp groove, if that was what you were using as a "marker" for your OAL.

The listed OAL in the Lyman Cast bullet Handbook is as you said, 1.03 for the 9mm, so that would work.

If you want to load it out further that would be fine as well since you are lowering pressures by making the area/volume of the case larger when you seat further out.

You can use two methods to find the max chamber allowed for "that" 9mm, by using either taking a case that hase been expanded to fit the boolit & then take a boolit and set it into the mouth of the case, then place the two into your barrel & push on the case until it reaches flush with the barrel "hood". { Or you can just use your seating die in small increments to seat the boolit more & more until it fits.}
What you are doing is getting the length of the chamber from the hood to the rifling. When the case is even with the hood doing it that way the length you have is the max OAL for "that" pistol.

Here is a chart that shows how to look at the "hood" to do a plunk test. It is for a 45 ACP, but the 9mm should be similar. Third example from the Left is what you would like to see.



The other method is to use two dowels, a short dowel & one longer than the barrel. A member here,( who just posted above) Dusty Bannister, wrote up a great description on how to do the dowel method. Below contains both rifle & semi auto handgun methods. the description for the dowel method is there:

Here is one of Dusty Bannisters posts about the "Dowel method" to determine OAL:
{He/Dusty, posted while I was typing this post up.}

Cleaning rod/dowel method of finding cartridge OAL

This is what I use for my guns to determine the max OAL and this eliminates any question of the crimp, incorrect case prep, or other operator induced error.

This method works well on rifles and single shot pistols as well as Semi-autos. You can use a flat tipped cleaning rod, or flat tipped dowel rod. You will also need a sharp pointed pencil, a short dowel and a bullet sized but clean, of the type you are going to load.

For Rifles
Make sure the chamber is empty. Close the bolt, and be sure the firing pin is retracted into the bolt. Insert the dowel or cleaning rod and hold it against the face of the bolt. Mark the rod at the face of the muzzle. Remove rod, open bolt and remove it from the action. Insert the bullet into the breech and hold it snug into the rifling. While in that position insert the dowel or rod again, and with it firm against the nose of the bullet, mark the rod at the face of the muzzle.

The distance between the center of those two marks is the max cartridge OAL for that rifle, with that bullet sized to that diameter.

For Semi-autos
Remove the barrel from the slide and make sure it is clean and free of leading or other debris in the barrel and chamber. The dowel or cleaning rod needs to be longer than the barrel. Hold the barrel, muzzle up, and place the barrel hood on a flat surface like a table top. Insert the dowel or rod from the muzzle and mark the rod exactly flush with the muzzle. Remove the rod and insert the bullet you intend to use into the chamber and lightly press and hold it in place with the short dowel. Place the assy muzzle up on the flat surface. Insert the rod/dowel into the muzzle so it rests on the nose of the bullet and again mark the rod exactly flush with the muzzle. Remove and set the barrel aside. The distance on the center of the two lines is the cartridge OAL. Seat a dummy round to this length, or slightly shorter and begin to apply the taper crimp until the dummy passes the plunk test. This is the optomum cartridge OAL length for this bullet in this gun.

You may need to adjust the seater to shorten the OAL if this does not feed from the magazine, but generally this will be a great fit. Remember, if you seat and crimp in one step, you might force a slight ridge ahead of the case mouth and that will screw up your seating.
Dusty

Source: http://castboolits.gunloads.com/show...=1#post3560663

Once you have found your Max. OAL for "that" boolit in "that" 9mm chamber, write it down & you can use it as a reference each time you load. Obviously the OAL of 1.03 is what the manuals say for that "min" OAL in the load dat & if you like just use that as the deepest you want to run the boolit/shortest OAL.

Now, if the Max. OAL is leaving the boolit far enough out that you see the lube groove, you will likely want to seat "that" boolit out only as far as to cover up the lube groove, or shorter. Then, you can adjust from "that" OAL back to the 1.03 manual suggested load data OAL. ( Your chamber may be larger and allow for the boolit to be out past that lube groove, but for "that" boolit I would suggest you at least cover the lube groove & go from there.



The next step after deciding what the OAL is that will fit the chamber, then you need to cycle a dummy round to see if the round fits the mag all the way thru chambering & then to extraction. A "Cycling Test".
If it fails to pass thru the whole of a "cycle", then you will have to adjust the OAL to make the round be able to function thru all the cycling steps & that will help decide what OAL, or range of OAL, that you can use in "that" handgun with "that" boolit..

G'Luck! & I hope I was able to help.

[Russman]

I have to seat the bullet in at 1.030,isn’t that going to increase pressures and maybe cause something bad.i just tries to chamber one at1.080 and it Locked my gun up.If the book says1.030 and it fits the plunk test then I should trust that right?

[JBinMN]

I have to seat the bullet in at 1.030,isn’t that going to increase pressures and maybe cause something bad.i just tries to chamber one at1.080 and it Locked my gun up.If the book says1.030 and it fits the plunk test then I should trust that right?

Yes. Then you will be fine if it "plunks" right.

You can continue to try the options mentioned above by all, but you will be just fine using that OAL of 1.03. By choosing to follow the Manual OAL limitation, you will be safe. If you choose to make the round longer then you will also be fine in regard to pressure, but that is where, as you saw with the 1.08, that your handgun "tells you" that that particular OAL is too long. { by doing a "cycling test")

Just do not load in any deeper than the 1.03, as that is where you would likely start to cause pressures to rise, & that is not usually a good thing.


G'Luck!

[Russman]

The last post by jb helped explain some of my issues.Im not so worried about lube groove now as I thought it was the crimp groove and didn’t think I could seat past it.I will load some more in a bit and give you an update,thanks again!

[Kenstone]

Simple way to determine max OAL
OAL
Find a fired case that the bullet just slips into with some resistance.
With the bullet barely into the case push them into the barrel with the shortest throat. You'll feel the bullet hitting the rifling, continue to push until you feel the case hit the chamber shoulder.
Carefully remove the case/bullet assembly, pinch the case/bullet juncture between you thumb/index finger, and measure the OAL with a caliper.
That measurement is the max OAL for that bullet in that barrel.
No research of conflicting data/opinions or interpolation, just a direct measurement.
Do it a couple of times, if you like, to check for consistency.
just the way I do it

I have found brass wall thickness (9mm) can vary from 0.009 to 0.012 and loading a 0.358' bullet in a case with a thicker wall will affect the plunk test.
So 2 x 0.012 + 0.358 = 0.382 and that's the sami diameter of the chamber and the sami dia for a cartridge is 0.380"
So some brass sorting by brand/wall thickness will help.
Note: there are tolerances in the Sami document which I ignored here
(sami file too big to attach here)

Confession: I have experienced the same problem as the OP and have been pushing the 0.358 bullets through a Lee 0.357 sizing die

[Russman]

Sounds good kenstone.I wasn’t thinking about the case wall thickness.I will factor that in as well.

[JBinMN]

Simple way to determine max OAL
OAL
Find a fired case that the bullet just slips into with some resistance.
With the bullet barely into the case push them into the barrel with the shortest throat. You'll feel the bullet hitting the rifling, continue to push until you feel the case hit the chamber shoulder.
Carefully remove the case/bullet assembly, pinch the case/bullet juncture between you thumb/index finger, and measure the OAL with a caliper.
That measurement is the max OAL for that bullet in that barrel.

:

I admire your better way of writing the first method to figure out Max. OAL that I mentioned in my earlier post. I do not have the "way with words" that others have & just try the best I can, to put into words what I do. Apparently the way I described the steps were not as clear as your post seems to be, but that is just fine since it got across apparently.


Thanks for putting the process into such a concise & clear way.

In the future I will likely use your description of the steps to take to set up Max OAL, the just the same way as how I have used Dusty Bannisters, "Dowel Method" write up in the past to try to help others.

It makes things a lot easier for me just to use others "way with words" than for me to try to type it out, and I like that.

[PowPow]

Also, when you're applying crimp in cartridges that headspace on the case mouth (like nahmeel), your goal is to remove the flare first. Once you have your adjustment that removes the flare, add a tiny bit at a time more until you're convinced that bullet setback is unlikely. You can try pushing the bullet in against your bench, or take measurements. That's normally 1-3 thousandths beyond straightened width. Any more than that and you start deforming the bullet and then the case.

[WheelgunConvert]

Just a little more on JBs diagram in post #5

Beretta M9/92fs like designs have the hood on the slide rather than the barrel. This makes the cartridge rim extend a bit further out than the diagram. My 1911s are just like the diagrams.

Bevan

[Kenstone]

i just tries to chamber one at 1.080 and it Locked my gun up.

I would advise not to "chamber one" as a test of ammo but rather do the plunk test with just the barrel, removed from the gun.
It's way safer...

[Eddie17]

Not deep enough!

[Russman]

Your insights have been helpful once again.Im glad I have a place to go for this valuable information,happy reloading and casting all.Im sure I will have a bunch more questions!

[Tom W.]

My Ruger will pass a plunk test with almost any load that I make, but my CZ will jam if the boolit isn't sized to .357....

.358 shaves off a tiny ring of lead that gives me fits.

[mdi]

The Lee "1R" bullets are more "blunt" than the normal round nose bullet. So, they must be seated deeper than a standard RN...

[Kenstone]

My Ruger will pass a plunk test with almost any load that I make, but my CZ will jam if the boolit isn't sized to .357....

.358 shaves off a tiny ring of lead that gives me fits.

OK then
You (and @Russman too!) need to get you one of these expanders and put it in your 9mm expander die:
https://www.titanreloading.com/lee-s...?search=SE1699
Thank me later
You don't use a Lee die?...never mind then

[PowPow]

OK then
You (and @Russman too!) need to get you one of these expanders and put it in your 9mm expander die:
https://www.titanreloading.com/lee-s...?search=SE1699
Thank me later
You don't use a Lee die?...never mind then

Double Alpha makes excellent powder through expander dies for those with Dillon presses.