9mm: Case Gauge = Pass; Plunk = Fail

[otisrush]

I'm befuddled..........

I recently decided to start using the Lee FCD on my 9mm. (I don't want to start a discussion on the FCD and whether its necessary or not. I'm giving background on why I am where I am.) So as a result I reconfigured my bullet seating die (RCBS) to not crimp since I'd do it with the FCD.

I had my barrel and case gauge on the table and made sure the COLs and plunking and case gauge results were all copacetic. I worked up a load and found one I really liked. So I loaded up some now that I knew what my go-to load is with my dies all reconfigured.

Now? They don't plunk. They don't drop quite down far enough as a plunkable round does. And they don't fall out on their own. They fit in the case gauge just fine.....but they don't plunk.

I know it's not a COL issue. I've loaded these bullets (124g Zero Bullets FMJ) to longer than what I am now and they've plunked OK. So I'm figuring it's a diameter thing. But, as I said, it passes in the case gauge.

The mouth expansion felt a bit small when I was seating bullets, so I wondered if some bullets were seated cockeyed. I increased the mouth expansion a bit to get a better pre-seating placement on the mouth but.....same results.

If it's not COL and it fits in the gauge, why would it not plunk? The gun is a Walther PPQ 5" barrel if that matters. The Sharpie test didn't tell me anything. I was actually going to smoke the case with a match but today's "safety" matches are so darn safe I can't get them to light! ROFL So I haven't done that yet.

Comments?

Thanks.

OR

 

[wally]

The gauges are nice, but the gun's chamber is the ultimate referee. OTOH you could have an out of spec barrel, worth contacting the maker.

 

[higgite]

What case gauge are you using? Most common ones, Wilson, Dillon, etc., don't have a leade like a barrel does. Bullets will drop straight through them. Point being, if it is an COL issue, the gauge won't detect it. Have you tried seating the bullet deeper or are you assuming it should be okay from earlier loads?
Edit: Forgot to ask obvious question... is the chamber clean?

 

[otisrush]

It's a Lyman case gauge.

I'm assuming deeper seating won't cause them to plunk because of previous loads. But I realize that is an assumption. So maybe I should try that to confirm either way.

 

[Rule3]

But what is your diameter at the case mouth after you crimped them? If you did not taper crimp enough to remove the flair, then they may be hanging up on the case mouth.

As far as the gauge, we don't need no stinkin gauge. Use your barrel.

 

[otisrush]

But what is your diameter at the case mouth after you crimped them? If you did not taper crimp enough to remove the flair, then they may be hanging up on the case mouth.

As far as the gauge, we don't need no stinkin gauge. Use your barrel.

Mouth diameter post-crimp is .375"

 

[Load Master]

Mouth diameter post-crimp is .375"

otisrush, I would suggest taking a Sharpee and coloring up one of the rounds and do the plunk test. This will at least show where the interference is and might help you to solve it.

 

[otisrush]

Thanks.

I'm a bit embarassed - but I just tried seating the bullet a bit deeper and it did plunk. My befuddlement continues.

I can't explain it. But, YET AGAIN, I'm bitten by the "Do you know what happens when you ASSUME?"

The investigation will continue.......

Man....this seems very weird to me.

 

[Load Master]

Thanks.

I'm a bit embarassed - but I just tried seating the bullet a bit deeper and it did plunk. My befuddlement continues.

I can't explain it. But, YET AGAIN, I'm bitten by the "Do you know what happens when you ASSUME?"

The investigation will continue.......

Man....this seems very weird to me.

No reason to be "embarrassed". Anyone who has reloaded for more than year who has never screwed something up would be lying. I have a personal collection of them I keep as reminders on a self above my reloading bench.

 

[Sunray]

Only gauge that matters is the chamber.
"...the FCD and whether its necessary..." Only matters if it's not taper crimp. And Lee says their 9mm FCD is a taper crimp. There is no measuring crimp. Crimp is 'enough' or 'not enough'. And sometimes 'too much'. Possible that the die isn't set to crimp enough.
"...I'm befuddled..." You'll get used to that.

 

[Walkalong]

You can measure crimp. I use a Wilson gauge to check all my sized brass. I scrap any that don't fall out from their own weight. Doing this ensures all my reloads will fit my tightest chamber (EMP). I set my C&H taper "crimp" die to remove the bell on the shortest cases, which means the longest ones will get a hair (.001ish) of inward "crimp".

The "Plunk Test" The round has to chamber without the bullet being interfered with by the throat or the lands. Without actually testing this by seating long enough to not "plunk", then shortening a little at a time until it does, we don't know what the longest OAL that will "plunk" is.

The Lee FCD will usually remove all the bell even when the crimp part is up off the case, simply because it is "post sizing" to a diameter that will fit SAMMI spec chambers. This is exactly what it is designed to do, make sure the round fits, diameter wise at least. It can't fix an OAL that is too long of course.

I have no doubt some FCDs get set improperly for the crimp part. Why not, we see it with other crimp dies as well, right?

 

[meesterdon]

You are not screwing up. The PPQ is a tight chambered pistol. Some bullets have to be seated deeper than your case gauge indicates. Don't ask me how I know.

 

[Axis II]

you said you found a good load so just remember when your seating deeper to get them to plunk your making pressure go up.

Sorry I cant help with the why it plunks or doesn't. I do know when I FCD 9mm some I can feel it really ironing out the bell and some its like it never touched it. these rounds get plunked just to be sure and never an issue.

 

[Walkalong]

I do know when I FCD 9mm some I can feel it really ironing out the bell

If you can feel the FCD ironing out the bell compared to the force it exerts post sizing, you're really good.

and some its like it never touched it. these rounds get plunked just to be sure and never an issue.

If they pass through the FCD without being "post sized" I would expect nothing less.

 

[Axis II]

If you can feel the FCD ironing out the bell compared to the force it exerts post sizing, you're really good.

If they pass through the FCD without being "post sized" I would expect nothing less.

I think I understand what you mean. Lol. I used mixed cases and some It feels like the FCD is actually the size die but not as rough. some it doesn't feel as hard. I have pulled some plated after FCD and measured them for the heck of it and no change I can see.

 

[otisrush]

You are not screwing up. The PPQ is a tight chambered pistol. Some bullets have to be seated deeper than your case gauge indicates. Don't ask me how I know.

As a shooter I love the PPQ. As a reloader.....well.....it is quite frustrating.

I can't figure out what is going on. I know it has to be me. It's like a gnome went into my safe one night and put a different barrel into the beast.

I started completely over this morning. I "unadjusted" all dies, starting with the expander, and went through the whole process. The max I could get to plunk was 1.095". Even that was a little inconsistent. So as of right now I'm thinking I'm going to work up a load at 1.090". Man....that is feeling SHORT!!! How do folks decide what COL to load to compared the max COL that will plunk? Do you take a certain amount off of max plunk length as a "safety" factor?

I'm most definitely NOT going to just seat currently loaded rounds deeper. Readers don't need to be concerned about that. Hopefully they'll fit fine in my Hi Power. Compared to the PPQ the Hi Power seems to have a spacious, long, luxurious chamber. ROFL If they don't fit in the HP......I'll warm up the bullet puller!

OR

 

[Load Master]

Did you color a round and test to see where exactly where it is making contact?

 

[mjsdwash]

id'e guess that Lee FCD is swagging the plated bullet outward slightly have you measured the diameter at the bullet. crimp and case?

 

[otisrush]

This is getting interesting......

Based on Load Master's question I produced the results in the attached photo. My Sharpie was too permanent. It wouldn't mar where the round was hitting. So I smoked the bullet and case with a match. It appears just above the mouth is where there is contact.

AND....that area is about .001" wider at that point as compared to the rounds that do plunk. (.356" for rounds that don't plunk. And .355" for rounds that do.)

So....for those who are more knowledgeable than I am: Does this .001" diff seem plausible to be the issue? I wonder if mjsdwash is right....that the FCD is causing a change in the bullet profile. If so, it appears I need to lighten the crimp a bit.

 

[meesterdon]

As a shooter I love the PPQ. As a reloader.....well.....it is quite frustrating.

I can't figure out what is going on. I know it has to be me. It's like a gnome went into my safe one night and put a different barrel into the beast.

I started completely over this morning. I "unadjusted" all dies, starting with the expander, and went through the whole process. The max I could get to plunk was 1.095". Even that was a little inconsistent. So as of right now I'm thinking I'm going to work up a load at 1.090". Man....that is feeling SHORT!!! How do folks decide what COL to load to compared the max COL that will plunk? Do you take a certain amount off of max plunk length as a "safety" factor?

I'm most definitely NOT going to just seat currently loaded rounds deeper. Readers don't need to be concerned about that. Hopefully they'll fit fine in my Hi Power. Compared to the PPQ the Hi Power seems to have a spacious, long, luxurious chamber. ROFL If they don't fit in the HP......I'll warm up the bullet puller!

OR

Once again it is not you. The PPQ is a tight pistol. Tighter than your cartridge gauge. Certain shaped projectiles will need to be seated deeper to fit the PPQ than they will for your other 9mm pistols. Rounds that will work in a RAP, G19, or Range Officer sometimes will not plunk in the PPQ. Fact of life. Ammo sized for the PPQ will work in any other 9mm on the planet BUT not the other way around. I went through. everything you are experiencing and now work up and size (COL) all 9mm loads for our PPQ. This ammo works in all our nines.

 

[Walkalong]

That's kind of strange where the marks are on the bullet and below the case mouth. That does look like it is over crimped. Either the camera is laying tricks, or the bullet is wider at the marks than at the case mouth. What OAL is the round in the pic?

How did you adjust the crimp part of the FCD? It's difficult/impossible to go by feel because of the resistance on the carbide ring on the case. Run the crimp adjustment way up so it makes no contact, run the round all the way into the die, the run the crimp part down until it touches the round. Pull the round out, turn the crimp adjustment down another 1/4 turn and try that.

 

[otisrush]

That's kind of strange where the marks are on the bullet and below the case mouth. That does look like it is over crimped. Either the camera is laying tricks, or the bullet is wider at the marks than at the case mouth. What OAL is the round in the pic?

How did you adjust the crimp part of the FCD? It's difficult/impossible to go by feel because of the resistance on the carbide ring on the case. Run the crimp adjustment way up so it makes no contact, run the round all the way into the die, the run the crimp part down until it touches the round. Pull the round out, turn the crimp adjustment down another 1/4 turn and try that.

I think the bullet is wider at the marks than at the mouth, by about .001". The COL in the pic is most probably 1.115". (I've got so many dummies lying around as a result of trying to diagnose this it's hard to keep them straight.)

The bottom line is I can't get any 1.115" to plunk, be them crimped or not. I can't fathom how/why I had (or thought I had) that length plunking OK 10 days ago. No matter how I mess with that length now it will not pass the test.

The longest I can seem to get to pass is about 1.095". And even that is intermittent. So I just did some trials at 1.090" and they all did fine.

Re setting the crimp: I followed pretty precisely the Lee instructions: A round was run up into the die with the crimp adjustment set way high. I tightened the adjustment until I just began to feel resistance, and then I went from there.

In order to replicate the precise order that I'll be actually loading with I loaded 3 dummies to 1.090". Then I crimped one with "Resistance + 1/2 turn", one with "Resistance + 3/4 turn" and one with "Resistance + 1 full turn". I wanted to see if amount of crimp would impact plunkability at the 1.090" COL. All three crimp levels passed plunking fine. My current thinking is to work up a load at this 1.090" COL level.

A further question: Do people check COL changes other than setback from feeding from mag to chamber? I'm planning on checking the COL after it has been chambered to see if the bullet moves from hitting the feed ramp, etc. But do I need to worry about checking bullet movement for rounds that have sat in the mag and gone through 9 firings? Is checking/worrying (and ensuring) no movement at that level in the "prudent" category or the "anal retentive / overthinking" category?

Thx.

OR

 

[Jim Watson]

That is how I adjust my CFC die. I am down half to 3/4 turn on the knob.

I have the 9mm Lyman "Maximum Cartridge Gauge." It passes nearly all my CFC loads and even the few rejects will "plunk" and shoot. But I don't have a PPQ. The gauge will pass a .355" bullet freely and a .356" with a fingertip push so it does not gauge for bullet protrusion from the case.

By spec, a minimum chamber should accept a maximum cartridge. The SAAMI drawing for 9mm chamber shows a throat tapering from .358" at the chamber mouth to .354" about .04" in front of the mouth, down from there to barrel diameter. Which is interesting because nominal groove diameter is .355". So there is not much room for full diameter bearing surface showing out of the case. My present loads are about .353" at the case mouth, using plated bullets for economy's sake.

But Walther is not a member of SAAMI. The CIP chamber has a smaller and shorter throat.
http://www.cip-bobp.org/homologation/uploads/tdcc/tab-iv/tabivcal-en-page28.pdf

Are they undersize by CIP? Might be, a lot of US manufacturers are quick to advertise "minimum match chambers" which translates to undersize.

 

[Load Master]

OR,
Nice job on the bullet to chamber test. It is telling. First off, by your photo the crimp is a bit too much. Back it off. It may even be distorting the bullet. If you find with your pistol that you have to use 1.090 that should be fine, just start with a light load and test for proper gun cycle. Slowly increase until the gun cycles but know that you can not load to the max with the shorter COL.

Keep in mind that the case mouth is what the 9mm uses to head space the round.

 

[higgite]

FWIW, I used to load that bullet and found that quite a few measured .356” in diameter, but they all plunked quite well when COL was adjusted to not hit the lands, even in my CZ which has a notoriously short leade. I agree that the round in the pic looks overcrimped. That might be bulging the case just enough below the mouth to leave the marks showing on the case.

My PPQ45 also has a short leade, but I can't speak for PPQ 9mm.