yet another 9mm leading thread

[reddog81]

I use powder coat so don't have anything to add other than 9mm has given my more problems than any of the other calibers I load - .38/.357,.44, .45, 10mm, light .30-06....

[asmith80]

I've been exchanging PM's with Dusty Bannister and he brought up the point that maybe N320 isn't that well suited to cast bullets. It's a fast burning powder, and it may be that it's too fast for what I'm trying to do. That would explain why I got better results with Unique, and no matter what I did with N320 I was having issues. I'll know for sure after I test out this latest batch of rounds.

[Dusty Bannister]

What I said was that since there is no data in the Lyman book for heavy for caliber bullets in the 9MM it might not be the best choice for your application. Nothing wrong with fast powders and cast bullets. Just not your heavy for caliber 9mm application.

[asmith80]

Ah, gotcha. Sorry I misspoke

[DougGuy]

ETA: just checked the pm DougGuy sent when he throated this barrel and he said his cutter was getting a little worn and he wasn't sure .358 bullets would work, but .357 should be fine. Wish I had remembered to look at this earlier. I've loaded up 20 sized to. 357 and 20 at .356 with the N320 loads. If I can get to the range tomorrow, we'll see if that works

If it plunks it should shoot fine. If you are sizing to .358" and they go into the chamber without resistance, this is as it should be and I would stick with .358" because it doesn't seem to be a contributing factor to the leading from what I am reading. If you are pulling boolits and they are miking .358" then you know your crimp is not sizing them down in the case, so I would try some different powders for sure.

Most of the time throating really reduces or completely eliminates leading in an auto pistol. I usually hear reports of results like Thumbcocker posted. I'm using Unique and 231 in my 1911s and they are throated out the same way and I never even need to clean them.

[Texas by God]

Is it the Lee 124gr tumble lube bullet?
Notorious for leading.

For sure. It left SPIRALS of lead in a RugerP89 that I owned.

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[asmith80]

First off, I really want to thank everyone that's contributed to helping me out. I'm still fairly new at casting and cast bullets, so my troubleshooting abilities aren't quite robust enough yet, and you guys have really given me lots of info and direction.

So I went out today with the SP01, but this time I loaded up the 155 gr and135 gr bullets with Unique. After thinking about what you guys have been telling me I may have been making two mistakes with using N320 before.

First, with the 155 gr. loads, I may have been compressing the charge which lead to the problems I was having. I'm thinking N320 may just fill up too much of the case to use with these long heavies.

With the 135 gr. my issue may have been loading them at max charge weight. Totally separate issue from the 155s but giving me a similar problem. I'll keep playing around with N320 and this bullet, but I'll redo my ladders from scratch to make sure I'm in the safe zone.

I started from scratch with Unique, as if I was working up loads for the first time. I double checked all my numbers with three different sources. I worked from 4.5 grs up to 4.9 with the 135 gr. bullet. All loads gave me good accuracy, but the best thing was, none of them leaded the barrel. In fact, after running a wet patch followed by a dry to get the carbon out, they were clean as a whistle.

I only had one load ready for the 155s, 3.4 grs of Unique, which I think is actually a little less than the starting load according to the Lyman 44th edition cast bullet book. But that was also for a 158 gr. boolit, so I should be ok. Again, good accuracy and no leading.

I did resize everything to .357, and while I don't know if this helped, it certainly didn't do anything negative, so I'll likely keep doing it just to be on the safe side.

So does anybody see anything I might've missed, or some way I might be looking at the data wrong?

[Plate plinker]

Glad to see you have found the way forward. Good work.

[meotai]

I was able to get the 155gr TC Elco lead free with WST. With titegroup, it was leading & keyholing. With WST, clean barrel & more accurate.

[asmith80]

What charge weight and OAL did you use?

[meotai]

3.3gr WST & 1.14 OAL on the NOE 358-155 TC ELCO. I don't remember the exact fps. It was above 125 power factor though. But not more than 135 power factor.

[sharpshooter3040]

That's about the same load I shoot in my revolvers with the exception of the bullet. I shoot the lee 115 wc 3.3 gr wst. My allow is somewhat softer and allows for obturation at target velocity. The harder the alloy the more it will lead up. Won't seal in the grooves all the way and will strip and flame cut. If keyholes happen that's what's going on. I use range scrap and 10%tin with real good results. Just a thought. I've been at this about 40 years now.


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[asmith80]

I found another wrinkle in this ordeal today. I went back and redid all my ladders making sure I was starting low and gradually working my way up to a decent load. I even went out and got a chronograph so I could be getting as much data as I could while I worked up these loads.

I used Bullseye, Power Pistol and more n320. I used the data in the latest Lyman book for 140 gr. boolits (I'm sticking to testing with the 135 gr. I have just to keep things simple) and figured I could work my way up to a decent load from there.
First loads from all three powders were giving my around 920 fps on the low end to 957 fps on the high end, so I knew I wasn't accidentally hot rodding these. No bad pressure signs, good accuracy, mild recoil.

Checked the barrel and all three loads left smears of lead in the barrel. I did clean after each round of tests, so I started with a clean barrel each time I switched powders.

So in my frustration I started breaking down the rest of what I had loaded when I got home. Just out of curiosity I measured each bullet just to make sure it wasn't something simple like swaging the bullet down. And sure enough, most of the .357 bullets I had loaded were measuring .355. Not all of them, but a significant amount were.

So I reset my taper crimp die and made about 5 or 6 dummies and pulled them to see if I was getting the results I wanted, and then I locked that sucker down.

I'm not sure why some were swaged and some weren't, maybe the die was loose and in tightening it down as I went I was over tightening it or something. Either way, that may be what has been giving me fits this whole time

[DerekP Houston]

variation in brands may have different thickness of brass? That's my guess at least.

[asmith80]

I am using mixed brass with some military cases in there, so that's a definite possibility. I'm going to do a few more dummies just to check everything and I'll make sure to use a couple pieces of military brass in there

[Virginia John]

I personally shoot .357 in my 9mms. I like the 124/125 gr TC or LSWC. By using a light load of W-231, about 3.7 to 4.2 I have no leading. I'm not sure it was mentioned but you might want to experiment with different powders and varying measures to test the effect.

[asmith80]

So on the recommendation of a PM I received, I tested out the hardness of the boolits I was trying to get to work, and I think I figured out why they were swaging down to .355. Everything I've cast recently was from a batch of range lead that I got, and not thinking, I cast using it straight. All the boolits from this batch were testing out at 8 bhn with my Lee tester. Way too soft for the velocities I was trying to get.

So I emptied out the pot and cast up a bunch using some COWWs and 2%tin. These came out around 14.3 bhn air cooled. After coating some with Hi-Tek and baking they were around 11.3. I'm going to let this batch age harden for a couple weeks before I get really serious about testing them, but just for kicks I loaded some up to see how they would do.

Results were pretty positive. A 3.0 gr. charge of n320 gave me a clean barrel, but only about 819 fps. So not enough for power factor. I may try a 3.2 gr. charge just to see if I can keep things lead free but also get up to a minimum PF.

3.7 gr. Bullseye gave me a little leading near the chamber but that's it, and it came out with a tight patch, no brush needed. This was around 950 fps so this one looks pretty promising.

The last one was 4.6 gr. Power Pistol which was coming out accurate.... and then I accidentally shot the chronograph

What I did shot of this one, left some leading but not as bad as before.

Overall I'm feeling pretty positive about where this is going. I think I'm getting this issue nailed down. We'll see what happens in a couple weeks after my new batch age hardens.

I may pull some out and size them to .358 and load them up just to see if that makes a difference, but I'm not expecting anything, more just out of curiosity.

[asmith80]

Had a chance to get out to the range today. Had my new chronograph, thanks to Amazon, and I made sure there was no way for me to put unintentional holes in it

I had 3.2gr of n320 loaded up two ways. One with bullets sized .357 and one sized. 358. This was a very accurate load, putting 5 shots into 2.75 inches at 25 yards. Velocity hovered right around 900 fps, so just barely made power factor. The .357s left a little leading near the chamber. Not sure why it was just in that spot.

The .358s left the barrel clean.
So one more piece of the puzzle seems to be falling into place. I may try bumping up to 3.3 or 3.4 gr of n320 just so velocity is comfortably in the 900s, and I want to try the 3.7 gr of Bullseye with some .358 sized bullets and see what happens there

[NoAngel]

variation in brands may have different thickness of brass? That's my guess at least.

Absolutely.

No one wants to put the work in for the lowly 9mm but separate your brass! I've come to the point of using Win brass exclusively.

For anyone using a Lee factory crimp die; if you FEEL the bullet pass through the sizing ring you are most likely sizing the bullet down. Pull one and see for yourself. You can either stop using it as so many advise OR if you like the taper crimp it provides like I do, you can lap the ring open. It's NOT easy and will require a diamond lapping compound and LOTS of patience. It took me quite a while. I often wonder if it would have been easier to just use a cold chisel and break the carbide
ring out altogether.

[Beef15]

Absolutely.

No one wants to put the work in for the lowly 9mm but separate your brass! I've come to the point of using Win brass exclusively.

For anyone using a Lee factory crimp die; if you FEEL the bullet pass through the sizing ring you are most likely sizing the bullet down. Pull one and see for yourself. You can either stop using it as so many advise OR if you like the taper crimp it provides like I do, you can lap the ring open. It's NOT easy and will require a diamond lapping compound and LOTS of patience. It took me quite a while. I often wonder if it would have been easier to just use a cold chisel and break the carbide
ring out altogether.

You could just drive the sizing ring out with a brass drift or wooden dowel. It's just pressed in. Can be taken in and out a few times and still hold.

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