Lee Undersized Die and 9mm

[Gadawg88]

If your sizing die is set properly, it could be that your COL may be a little too long for the one barrel but not the other. The brass is not likely the problem. As stated in a prior post, the U die is mainly used to increase bullet tension. I have never had any issue with Win brass in 9mm or any other caliber for that matter. Blazer and Speer brass is thin and I have used the U die when loading it in 9mm to get required bullet tension.

 

[rfwobbly]

► The Dan Wesson chamber probably follows the chamber dimensions of their parent company, CZ. In that case the freebore is very short and you will have issues with excessive OALs. You are not helping yourself in this regard because 147gr bullets are longer than the normal 124gr 9mm bullet and there's only so much bullet you can bury inside the 9x19 case before the case buckles in the center.

Some experimentation will be required on your part to find a satisfactory OAL to use with this bullet-barrel combination. Bad News #1: You may not be able to use the OALs given in the load manual. Bad News #2: Nor can every bullet offered for sale be used in these short freebore barrels. But, only experimentation on your part will prove these statements true or false.

► 9mm Luger also presents a secondary issue in that the chamber is tapered, which can hide/ disguise taper crimp issues, and make them appear to be OAL issues, and vice versa. So in these instances you first have to rule out taper crimp as a possible suspect. IMHO, your taper crimp at the case mouth should measure between 0.376" and 0.378". In all cases it MUST be less than 0.380" when measured like this...

With taper crimp, "more is not better". You have definite parameters.

Hope this helps.

 

[wiiawiwb]

The taper crimp at the case mouth, when measured as you have demonstrated in that picture, for the rounds that do not pass the plunk test are between .367" and .370". That applies to 147 gr coated bullets or 124 gr plated bullets.

 

[kcofohio]

Here is something you could try. Pull the bullets from the offending cartridges. Then see if the cases will fit the chamber. That could at least rule out the COAL as the issue.

 

[wiiawiwb]

I do have the 4-die set and I am using the Lee FCD. Here is a picture of two different rounds that did not pass the plunk test.

The two rounds that failed are 1.159 in length. The typical round that passed is 1.160.

The round that passed is .387 wide at the base where indicated by the red arrow in the picture of two rounds. The two rounds that failed are .388 and .389.

I do have the 4-die set and I am using the Lee FCD. Here is a picture of two different rounds that did not pass the plunk test.

The two rounds that failed are 1.159 in length. The typical round that passed is 1.160.

The round that passed is .387 wide at the base where indicated by the red arrow in the picture of two rounds. The two rounds that failed are .388 and .389.

I went back and created a dummy round with no powder and no primer. I took a fresh case and reset the sizing die from scratch. I took a 147 gr coated bullet and seated it to 1.184 to start (way above max OAL) and the bullet passed the plunk test with flying colors. That indicated to me it wasn't the OAL that was causing the problem. I then seated it to 1.159 which is what all the other rounds in 147 gr have been seated to. I then crimped it as I did the others. It passed the plunk test.

I then measured the width at the base of the case as I did with the others before and it was .002 smaller. I think the issue might have been the darn resizing die was not all the way down. Even so, in the past 98% passed the plunk test. I bet with the slightly lower-set resizing die, it is now resizing the entire case as it should.

I'll reload some this weekend and see if that solves the problem and report back. I want to thank all of you here as you folks are so helpful. Proud to call you all of a friend.

 

[Walkalong]

It may be the base causing the problem, not the front.

.370 crimp is too much.

Hopefully the die adjustment solves the problem. If not you may need to gauge the sized brass and scrap a few here and there.

Adjust the die, size a bunch of cases, and check them with the barrel or a gauge before loading them. If some don't fit, turn them around and see if the base will at least start in there or not.

 

[Blue68f100]

Just be aware that there is some 9mm brass on the market that has a step inside the case to prevent case back. These will cause problems if a bullet is seated too deep, bulging the brass.

 

[ATLDave]

Great report/experiment, wiiawiwb. I owe you a beer!

 

[hdwhit]

The American Rifleman ... found the use of W-W brass caused big problems, which my experience confirms.

Huh? I wonder what the specific problems were? I'd like to be on the lookout for them.

I've been reloading for 38+ years but I've only been reloading 9mm for about a year and during that time I've loaded a few hundred WIN, WCC and WMA headstamp brass without any problem.

 

[Walkalong]

Me too, and over the years the only problem with WCC was some are crimped.

 

[Wreck-n-Crew]

I think the issue might have been the darn resizing die was not all the way down.

I agree. glad you got it.

 

[splattergun]

My 9mm all plunk easily in my P89, and have for years. My brother tried some of them in his M&P9. IN his S&W the slide failed to close completely on about 10% of my reloads. I decided to seat them a smidge deeper and they now cycle fine in his weapon. I reduced the oal by about 2 thousandths.
BTW, about 45% of my brass is Rem or R-P, another 45% is WIN or WCC. Never had a problem with either. No way am I going to listen to a vague reference to an ancient magazine article about lots of unspecified problems, even if it is claimed to be supported by an experiment that is just as vague. Winchester brass works fine for me.

 

[rfwobbly]

The taper crimp at the case mouth, when measured as you have demonstrated in that picture, for the rounds that do not pass the plunk test are between .367" and .370".

► That is WAY too much taper crimp !! You are most likely buckling the case during the application of that much crimp. Here are the SAAMI cartridge dimensions, the same as found in your manual...

The case has a constant taper, meaning that the point halfway between those dimensions is proportionally larger than the case mouth. So the center of the cartridge cannot be any larger than 0.385/0.386". Check that. It can be smaller, but not 0.0001" larger.

► The reason I say your taper crimp is too much is because the case mouth dimension should equal the bullet diameter (0.355) plus 2 case wall thicknesses at the mouth. Add that up and you'll end up between the numbers I previously quoted.

► You're not having trouble with these rounds in your Glock because it's a law enforcement weapon. It's designed to fire cartridges even when the mag is retrieved from the mud. That means the Glock chamber is cut with larger clearances. On the other hand, your Dan Wesson is a target gun. Its chamber dimensions are cut to very tight tolerances in an attempt to deliver very accurate bullet placement. The difference in those 2 worlds is not Ford vs. Chevy; it's more like bicycle vs. bulldozer. So your reloaded ammo has to meet the tighter specification.


Hope this helps.

 

[wiiawiwb]

It may be the base causing the problem, not the front.

.370 crimp is too much.

Hopefully the die adjustment solves the problem. If not you may need to gauge the sized brass and scrap a few here and there.

Adjust the die, size a bunch of cases, and check them with the barrel or a gauge before loading them. If some don't fit, turn them around and see if the base will at least start in there or not.

Here is a round which has been seated but not crimped yet. It is .371" at the case mouth before crimping. The center of the case is .374" without crimping and .381" at the base.

I then did a light crimp and it now measures .370" at the case mouth after crimping.

It plunks nicely.

 

[Walkalong]

Here is my round which has been seated but not crimped yet. It is .371" at the case mouth before crimping.

Interesting, I wonder if the seater is tight and squeezing it down. Or does the seater have a taper crimp built in and you have the die body too far down. Are you seating/crimping with one die or crimping after seating with a separate die? Sounds like you are crimping separately. If so, look at adjusting the seater die body up some, and of course the seater plug down.

 

[wiiawiwb]

Now, here is a 9mm factory round from Buffalo Bore. It measures .371" at the case mouth and .381" at the base. The case mouth is .001" larger than mine and the base is identical, which I've outlined above.

 

[wiiawiwb]

I have the Lee 4-die set so I am seating with the seating die and separately crimping with the Lee FCD die.

 

[wiiawiwb]

One more check....I just measured a MBC 125gr and Berry's 124 gr bullet that I've loaded and they come in at .370" and .371" at the case mouth respectively.

 

[gonoles_1980]

I use a gauge, I'd say 1-2% would fail the gauge if I didn't use the FCD to crimp. Also, with flat points you may want to try 1.08, I only use 1.15 for round nose.

 

[forrest r]

Just another opinion:
Sounds like you need to take your time and do some testing. There's 2 way to use the plunk test, so far you have only been using 1 of them. Take and size 50 cases and do a plunk test with them. They all should pass the plunk test in your bbl. If not either re-set/re-adjust your sizing die and redo the 50 piece of brass test.. If that doesn't work you probably have an oversized (too tall) of a shell holder. If all 50 pieces pass the plunk test it's time to move on.

Measure the base of the case then bell the case as you normally would and then measure the base of the case again. Do this to all 50 cases, make sure the base of the case is the same before and after belling. A lee 9mm factory expander plug next to a custom expander plug I made for the 9mm's. I load a .358" cast/coated bullet in all 3 of my 9mm's. As you can see the factory lee expander plug is designed for the shorter jacketed .355" 9mm bullets.


Adjust the 3rd die so it only seats the bullets, no crimp of any kind. After seating the bullet check the oal and then measure the base of the case and the mouth of the un-crimped case. Do this for all 50 cases noting the differences in the oal's. Also try the plunk test with the cases un-crimped, so bbl's are loose enough that the un-crimped brass will still pass the plunk test.

Finely crimp the bullets and do the plunk test with each round.

Doing this will not only test each stage of the reloading process, it will give you a real idea of what your dies are actually doing and the tolerances you are actually keeping with your reloads.

I'm not sure where you are getting the .370"/.371" from???? I just went and measured some cheap cbc ammo (.376") and some federal (.377") and some remington (.376") along with my reloads (.377"). I try to target a 3/1000th's taper on all my semi-auto ammo and straight walled cased pistol ammo when I use a taper crimp. The end result is case mouths that measure .377" with 1 every now and then measuring .378". I use a dial caliber and mics to measure my reloads with. I use test gauges designed specifically for setting these measuring tool to read accurately. Coupled with square gauge blocks.


When I seat the bullets I load I don't set the oal for the "MAX" most accurate with lead height. I set everything 10/1000th's less than the "MAX" oal. If you took your time and measured the difference in the oals of your 50 round test run you will see that the oals can and will very that much. Couple that with what others have said about the coating being different thicknesses on the nose profile of the bullets. Two of my favorite 9mm bullets that I use in 3 different 9mm's. The lee 125gr tl tc and the 125gr mihec fn hp. Both are loaded 10/1000th's less than the "MAX" oal using the plunk test.


While everyone does things differently, this is what I did to setup my dies to reload for the 3 9mm's.
Made sure the sizing die was adjusted correctly
Used the correct expander plug for the bullet being used.
Seat the bullet in 1 step to have a 10/1000th's (+/- 5/1000th's) less than max oal.
Crimp in a separate stage putting a 3/1000th's crimp on the case mouth (.377").

That mihec 125gr hp in a nm 1911, a 10-shot group @50ft with reloads using what's written above.


Playing around testing different hollow base pins/designs in a 150gr hollow based flat nosed bullet for the 9mm. A 10-shot group @ the 50yd line.


Back in the late 80's/early 90's we'd fit 6" 9mm bbl's in our 1911 38super race guns. Always set the reloads up the same way testing each phase of the process checking everything & getting it right & tight. Back then we ran full house loads of bluedot and the lyman 158gr rn cast bullets (free lead/358311). Shot countless 1000's of them, don't shoot 9mm's like I used to but I still shoot 5,000+ rounds of 9mm a year. I can't even remember the last time I've had a failure of any kind.

Just sounds like you need to go back and re-test from the beginning of the reloading process and nail everything down. When you get everything right you will be putting out countless 1000's of rounds with boring regularity.

 

[Walkalong]

Interesting, I just measured a couple of mine and they are at .377.

http://saami.org/PubResources/CC_Drawings/Pistol/9mm Luger - 9mm Luger +P.pdf (Only working in Internet Explorer right now according to the website)

 

[wiiawiwb]

Hmmm. I am going to buy a new pair of calipers and check it against the one I am using which is an inexpensive HF one. Maybe the one I have is just "off".

Forest...wow, very detailed, thank you. I am going to reread it again several times tomorrow morning over a hot cup of coffee.