9mm Lee dies & 358-125-RF mold 2-cav - ***???

[pbchunkr]

I've used Lee molds and dies for decades with no problems I didn't create myself.
This combo is driving me nuts.
I set seating depth and OAL can vary nearly .010" +/-.
Roughly 1/4 of my loads have to be coaxed to proper seating depth.
I can set the OAL, next few may be fine, next one long...in on the seater a tad...close, but down another touch - .010" under!
Pull it back out a bit, raise the seater a fraction, comes out, say, .010" over - turn the seater in an RCH (AKA a frog's hair) and OAL may come out .010" under again!
Next 2,3 or 4 may come out within a couple thou and then the dance again with more longs or shorts.
Since it's less than 50%, I can't really think the nose cavities could be enough different that one cavity seats fine, the other out of (my) spec but I can't think of anything else to account for it.
Anyone been through this? If not, next casting session I'll segregate the bullets from each cavity and see if, in fact, that's what's going on.
Thanks for lending a virtual ear.

[tazman]

How are you lubing your boolits?
Tumble lubing can cause buildup in the seating die and cause OAL difficulties(ask me how I know). I still use it anyway but have learned to live with it.

[pbchunkr]

RCBS Lubri-sizer and Lee Alox, tazman.
I've cleaned the seating stem to be sure buildup wasn't the prob and after posting above, went out to the shop, loaded another 35 rounds and 10 of 'em came out 5-10 thou short.
I checked my jacketed loads and they're within .001". I've loaded thousands of .32 S&W, .38 Spl, .357 Mag, .44 Mag, .45 ACP and .45-70 with Lee molds and dies and never had this crop up before.

[tazman]

The only other thing I can see is a poorly fitting nose plug with boolits that vary slightly on the nose profile. The nose punch probably doesn't hit/grip the boolit the same every time.
I would suggest getting something into the seating stem(possibly wax or epoxy of some kind) to give you a flat surface to push against the flat on the nose of the boolit. That should eliminate all variance from the process.
I had a similar problem with my 9mm dies and the Lee 356-125-2R a while back. In my case I adjusted the seating slightly deeper to eliminate the problem with the boolit hitting the rifling in my pistol.
This may or may not be an option for your situation.

[JeffG]

Not using that bullet for 9mm but ran into something weird like it once with 7.62x25 Tok, where cast bullets were large enough diameter they were interfering with die body due to their diameter. I ended up honing the die body as a result. It was fine with jacketed. Are you sizing the bullets or as cast? My 356-120-TC and TL356-124-TC are sized .357 so have never had issues with the Lee seating die. You should be able to remove the seating plug and see if there is interference.

[pbchunkr]

Sized to .357.
Excellent suggestions fellows.
I'll check for interference and, if that's not it, I suspect the flat plug will do it.
Tomorrow will tell the tale.
Thanks!

[bedbugbilly]

I don't use that boolit but I do use a 358-242 Lyman RN - and I don't think you are alone in the problem as I've read of it before and have even experienced it but not to the degree you are. I also tumble lube in paste wax/alox.

May be a stupid question but are you seating and crimping in two different operations? If not, try it and see if that has any results. And, if you haven't thoroughly cleaned your seating die, you might do that and see if things are more consistent?

taxman makes a good point on the boolit nose and the seating stem face. I'm pretty low tech when it comes to what I use to cast with - mainly range lead and from batch to batch, the hardness can certainly vary. I don't notice that so much with pistol cartridges - i.e. 9mm, 38 and 45 Colt but I have noticed the variance when it comes to using it for some of my bottleneck cartridges and the nose of the boolit related to seating stem face.

A little off topic but I have a mold that I use for my 30-30 that isn't quite as big of a flat nose as I would like for my Marlin and Winchester. When I cast, I cast from he same lot of range lead and will usually do 600 - 800 from the same batch. When I set them, with the neck tension I have, etc. I use a flat faced seating stem that will make the flat point just a tad bigger during the seating. That will, of course, affect COAL but with the lead being consistent, the COAL usually will only vary about .003 which will load and shoot just fine.

Keep us posted if you figure out what is causing your problem - we can all learn from it! Thanks and good luck!

[farmerjim]

I use this boolet for 38, 357, and 9mm. I have loaded over 15,000 without a problem. I Hi-Tek or powder coat all, and size 9mm to .357. I use a lyman M die, and lee seating and factory crimp dies. COAL stays within .002.

[bosterr]

I load that Lee boolit for a friend's 9mm. I've noticed that when I sit the boolit square on the flaired case they seat to correct OAL. Sometimes if I set it a bit crooked the boolit nose will want to grab the rough machining inside the round nose punch and will seat a bit crooked and be a little longer. Also check to make sure your primers are seated all the way in. Not likely your problem, but check to make sure. Are you loading these single stage or on a progressive?

[pbchunkr]

I hand prime and load in stages with separate crimp.
I'll try the flat-end plug and post results later today.
Thanks for the interest and help, guys!

[pbchunkr]

I filled the stem cavity with epoxy as tazman suggested with OAL +/- .003" on 10 test rounds so I'll call that good enough.
I use a Lee turret press which has some play in the disk fit so I suspect variation in the seating stroke speed/force accounts for some of it and, as bosterr commented, variations in seating straightness probably plays a part.
Thanks again for all you help, fellows.

[pbchunkr]

UPDATE -
Turns out all is not so well - more loading shows variation is still too much to suit me.
Shimming the turret disk to take out play didn't help.
I'm loading mixed brass and neck thickness/tension may figure in so next session I'll segregate 'em and see.
I'll post results when I have 'em.

[HeavyMetal]

Years ago I loaded for a 45 Colt SSA, the Lee seater die only seemed to know one depth: boolit seats with shoulder even with case mouth no matter where I have the die set at???

Removed die from press, removed internal parts completely and put die back in the press boolits seated with shoulder flush with case mouth!

The area in the dies was not large enough to allow my .452 cast boolits to pass into the area the seating stem occupied, they were actually catching on that area the boolit should have slid up into for depth adjustment.

a sample boolit and the die body was returned to Lee for adjustment, I got it back a week or so later, with that portion of the die enlarged just enough to allow .452 boolits into it and a short note telling me I should be shooting J word bullets in a six gun for best performance.

Please check you die body for interference between boolit and body of the die, if it don't fall through without help fix it.


Flex in your turret press may be the issue but I doubt it, still it is hard to help over the net and not be able to handle the problem pieces, LOL!

HM

[pbchunkr]

Yes, HM, JeffG suggested possible internal interference so I ckd that and not the prob.
At this point I'm leaning toward case mouth thickness variables as the source, but I hafta get to the range and "unload" some then cast more before I can check for that.