Leading with Lee TL356-124-2R

[802boomstick]

Hey guys,
Ive been shooting this Lee mold design for a while now through both my CZ p-09 and p-07 9mm's. I started using alox lube with wheel weight lead. A trip to the range and 150 rounds later my bore is horribly leaded (mucho scrubbing). I have slugged my bore to be about .3555 and the mold casts at about .3565. Now here is the real mind boggler...me and my buddy have switched to powder coating the boolits (wet black) and although now my boolits when finished are about .360 i still get leading about just as bad. Even after firing a few factory FMJs after my cast rounds.
Any experiences similar with this mold?

[petroid]

no xp with that mold but i PC. have you done the smash test with your boolits? I mean if you smash a boolit with a hammer does the PC stay on or flake off? if it flakes off, that's where your leading is coming from. Also, take a boolit and seat it in an empty unprimed case, then pull it and measure it. sometimes boolits can be swaged down by too tight a case until they are undersized. I had this problem with my 40 s&W until i got an oversized expander plug. Im still learning about alll this too

[bedbugbilly]

How fast are you pushing them? What powder and how much?

I'm using the 356-120 TC Lee and casting from range lead. They drop at .358 and I size them to .357 then tumble lube in paste wax/Alox and load over 3.5 gr. of Bulls Eye. I don't have a chronograph but my SR9 cycles just fine and I never have any leading.

I'd try using the same as you have been for the bullet and lube but see what happens if you slow them down? Just a thought . . . .

[nitrohuck]

I was there for these tests, as well as for the entire loading process from start to finish with the OP.

I've read some pretty unfavorable reviews for the LEE TL mold designs in 9mm, it seems (to my only partially-trained eye) that the little lube grooves get plowed over by the hot gasses and mowed down, allowing gas to cut by...

My thought was that powder coating should fix this problem, alas it didn't...

With a bore that slugs .3555-.356", and PC'ed boolits shot as cast (coming out to ~.359" after PC is applied) I am at a complete loss for what could be causing the leading...

By the way, these boolits that we tested were loaded over charges of Red Dot ranging from 3.4gs to 3.9grs, we aren't working with seriously hot loads here by any means...

P.S. - smash test on the PC boolit yielded perfect results, no flaking at all, "jacket" is in tact.

[802boomstick]

How fast are you pushing them? What powder and how much?

I'm using the 356-120 TC Lee and casting from range lead. They drop at .358 and I size them to .357 then tumble lube in paste wax/Alox and load over 3.5 gr. of Bulls Eye. I don't have a chronograph but my SR9 cycles just fine and I never have any leading.

I'd try using the same as you have been for the bullet and lube but see what happens if you slow them down? Just a thought . . . .

ya...thats our plan as of now. Im running 3.6gr of red dot and that was used to get good cycle and lock back on just the lead with no powder coat. I used the same load with powder coat but mabey dialing it down is the ticket....i wanna like this mold

[802boomstick]

no xp with that mold but i PC. have you done the smash test with your boolits? I mean if you smash a boolit with a hammer does the PC stay on or flake off? if it flakes off, that's where your leading is coming from. Also, take a boolit and seat it in an empty unprimed case, then pull it and measure it. sometimes boolits can be swaged down by too tight a case until they are undersized. I had this problem with my 40 s&W until i got an oversized expander plug.
Im still learning about alll this too

I just smashed one and the jacket stayed in one piece...no flaking or chipping. Loaded a dummie round and pulled it and she read .360 still. I have put one out then pipe with just a primer (oops) and measured and its about .356 and the jacket (still intact) showed no weird signs but i know that wont tell me much unless i have actually recovered a charged round. Possibly .360 too big (size it down)???....further research shows that many people do not like this mold...not much talk on the leading part though.......

[802boomstick]

I was there for these tests, as well as for the entire loading process from start to finish with the OP.

I've read some pretty unfavorable reviews for the LEE TL mold designs in 9mm, it seems (to my only partially-trained eye) that the little lube grooves get plowed over by the hot gasses and mowed down, allowing gas to cut by...

My thought was that powder coating should fix this problem, alas it didn't...

With a bore that slugs .3555-.356", and PC'ed boolits shot as cast (coming out to ~.359" after PC is applied) I am at a complete loss for what could be causing the leading...

By the way, these boolits that we tested were loaded over charges of Red Dot ranging from 3.4gs to 3.9grs, we aren't working with seriously hot loads here by any means...

P.S. - smash test on the PC boolit yielded perfect results, no flaking at all, "jacket" is in tact.

Found this

Sealing the bore. The microscopic defects discussed earlier are also the source of leading as a result of gas-cutting. Bullet lube plays a very important role in preventing this source of leading by acting as a sort of “stop-leak”. The most important bore sealing mechanism is obturation of the bullet metal itself, but the bullet lube can play a strong supporting role if the lube is of the proper consistency. When the hot gases driving the bullet start to leak through the channels left by engraving, they pick up lube and force it into the crevices as they both move forward. By filling these channels with lube, the flow of gases is effectively stemmed, thereby limiting gas-cutting. If these defects are sufficiently large (i.e. rough bore, undersized bullet, irregular lands/grooves, etc.) then the lube simply gets blown forward and out the bore, leaving the bullet naked and severe leading is the observed result. Once again, we see that the flow properties of lube are critical – if it’s too thin (i.e. liquid) and has a low viscosity, then this sealing mechanism is lost and the lube isn’t able to do its job because it’s an aerosol out in front of the bullet. Thus, the “stiffness” of bullet lube is a compromise between being fluid enough to be effectively pumped from the reservoir (i.e. lube groove) to the bullet/bore interface, and being thick enough to form an effective seal once in place. The old adage “Moderation in all things” once again holds true – viscous flow, with moderate thickness is a key virtue for a quality bullet lube. There is no such thing as a perfect bullet/bore seal, there will always be channels and defects that are not sealed. It’s a question of whether or not obturation and lube can team up and make an effective seal.

so mabey with no lube the TL design is no good

[nitrohuck]

you mean no lube on the PC'd bullet is no good?

we shouldn't need to lube them once PC'd anyway, defeats ze purpose,

more and more research is showing that this mold has a pretty bad track record with many members here. The PC should've fixed the leading issue, the boolit diameter is about right for a PC'd round, the load of ~3.5grs Red Dot is not a hot round, I am trying to think of other factors here and am sort of coming up at a a loss...

Also there is the problem that at 50 feet, fired from a rest, the groups look like they were shot by Hellen Keller... if they even stay on paper that is... we're talking 1 foot groups at 50'. Then we loaded up factory ammo and put three rounds into about 1" :killingpc

We have an XDm arriving this Thursday to test alongside the CZ P09, will see if it has the same issues.

[243winxb]

http://i338.photobucket.com/albums/n420/joe1944usa/Lee124grTCa.jpgPoor bullet design along with improper lubing can lead a barrel. The alloy should have 2% tin 6% antimony to get BHN 15,harder is better for high velocity using air cooled bullets. Slower burning rates of powder are better than fast when loading to maximum velocity. Make sure the bullet diameter is at least groove diameter + .001" or .002" larger. Yes, BB = Bevel Base. FB = Flat Base.

[nitrohuck]

234winxb

In your diagram above, what does BB and FP stand for? Beveled Base and Flat Base??

[petroid]

I use lee tumble lube mold in 40s&w and PC with HF red and no leading. I water drop out of the oven to harden. Have you tried/done that? Works in my 30 cal rifle too. Maybe a slower powder would help. Power pistol works for me

[Wally]

I shoot the 9mm Luger w/3.5 grains of Red Dot or Promo using the Lee (Non-TL) # 90239 120 TC bullet..very accurate. I tried the 125 RN-TL (90464) once and it was a disaster.

[Garyshome]

Try water drop. I don't use the TL mold.

[tyeo098]

Do you have enough lube?
Try Recluse 45-45-10 I had baaaaad leading with my CZ75:
http://i154.photobucket.com/albums/s249/tyeo098/Guns%20and%20Stuff/20131005_212634_zpsc044f012.jpg

Switched to Recluse 45-45-10 and lubed lots!
http://i154.photobucket.com/albums/s249/tyeo098/Guns%20and%20Stuff/CAM00122_zps26qh7zj5.jpg

Now I get no leading :)

[Maximumbob54]

Do a plunk test in the barrel. The whole thing should just drop in without needing to be pushed at all. You want to make sure the bullet isn't digging into anything to chew the coating or the lube off. I've read that some CZ's have a pretty tight or short jump to the bore. Your bullet may need to be seated just a hair deeper. That is a crummy bullet design with very little room for error. I went to the other Lee design with the regular lube groove and had far less headache. I also PC them now and they work fine again.

[802boomstick]

thank you all for the suggestions and knowledge. i purchased a lee 356-125-2r which is regular lube design and a flat (not beveled) base. hoping to have better results with both powder coat and lube. i will report back with results.

[tomme boy]

I had to switch to a 38 S&W expander to get my SAR B6 compact to stop leading. It is a copy of the CZ75 compact.

[JeffG]

Not sure if you have viewed http://castboolits.gunloads.com/showthread.php?121607-Setting-up-for-boolits-in-a-new-9mm yet but might be helpful.

I use 2 different Lee bullets in my 9mm S&W, the TL356-124-TC and 356-120-TC. I bought the TL design first in 2 cavity. I slugged the barrel and throat and it was .356. The throat diameter was the one I paid most attention to. I cast them in COWW, adding 3% time and age hardened for 2-3 weeks. These were TL'd in straight LLA, passed through Lee .357 sizer (which is actually closer to .3565) then lubed them again, drying after each coat. These were loaded over Unique and there has never been the first hint of leading. I DO get a little antimony wash near the muzzle but that will brush out in one stroke with a dry bore brush. I thought for a while I was having leading but have learned from others here and experience it was not. Bottom line, in my gun, it works, every time, and is accurate. Due to the design, I am able to seat the bullet long so it is in the throat till it almost kisses the rifling. That ends up being 1.145 OAL on mine.

I later bought the 356-120-TC in 6 cavity along with Lyman 4500 and .357 sizing die. I cast these from same alloy, load with same powder charge, use plain Lyman Alox stick lube and size to .357. Bottom line, it too works, every time, no leading with some antimony wash near the muzzle. It isn't possible to seat these as long but that seems to be fine.

I've since played with softer alloy, mixing 50% COWW and 50% pure lead, again adding 3% tin. All other lube, prep, sizing, aging, charging are the same. In short, they all work, every time, no leading.

I went to the trouble of mixing up 45/45/10 at a point. Beyond the fact it seems cleaner to work with, I personally found no improvement with it.

Good luck to you, maybe there is something in here of value to you.