Lead hardness - 9mm vs 45 ACP?

[Larryect]

Not the regular 9mm vs 45 thresd...

Have you noticed a need for harder lead in the 9mm?

I ask because I cast some bullets using essentially the same lead for both calibers. I am happy with the results in the 45. But the 9 mm is giving significantly more leading of the barrel.

The 9mm were made with the Lee 124 grain FP tumble lube mold, and sized with the Lee .356 sizer. Bullets were tumble lubed and loaded with W231 at 3.6, 3.8, 4.0. Near the end of testing about 80 - 90 rounds, I noticed the bullets were tumbling with the 4.0 charge.

As near as I can judge with the Lee hardness tester the bullets are about a BHN of 14.


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[armoredman]

Hmm, I use the Lee round nose tumble lube mold in my 9mms, and Lee Liquid Alox for lube, no leading. My lead is strictly straight wheel weights, as one industry spokewoman said, "Garbage lead!" I use Accurate Arms #7, maybe that's the differance?

[jim147]

You might try sizing to .357 if you have enough room in the chamber.

jim

[zxcvbob]

Try loading them without sizing.

[Larryect]

Okay, thanks.

I think straight wheel lead should be a bit softer. I am not real sure of the history on this lead. I inherited a bunch some time back. This was already in ingots. I pick the medium hardness ingots out of the bunch, melted them together and added a bit of lead free solder.

According to Lee's manual, if reading correctly, they recommend a max pressure of about 17k - 18k PSI for a BHN of 14. And the 9mm chamber pressure would be around 30k - 33k PSI. So, I was wondering if the bullets were too soft.

I'm happy to hear the Wheel weights work fine in 9mm. I did also get some weight variation from about 116 - 122gr. I figured that might be due to the 6 cavity mold. I did select bullets on the heavier end for testing.

It does make since to run them a bit larger. Unfortunately, it's going to be a while before I can try that. I will need to re-melt and re-cast them. I already sized all of them...

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[Griz44]

Lee Second Edition,
9mm pressures 32,000 to 34,000
45acp pressures 18,000 to 20,000
Page 134 (hardness vs pressure) sets your 9mm at 26 BH and the 45 acp at 15BH for optimum lead hardness for each round. I use this table when getting my alloy adjusted for all my cast lead, and have little to no leading.

Try it, you'll be a lot happier with the results.

[Larryect]

Thanks Grizz,

That is what I was looking at. I was wondering if people had real world experience verifying that guideline. Sounds like you do.

But, when I hear wheel weights work fine in 9mm - I just can't figure out the disconnect... armoredman - Are you heat treating or anything?

I have Linotype on-hand, so I can certainly make harder lead. But my understanding is that Lino is about 22. And pure Lino makes a brittle bullet. So, do you water quench to bring the hardness up without getting brittle?

Of course, I am just punching paper, so maybe brittle doesn't matter?

[Claude Clay]

some guns lend themselves to reloading for accuracy; p7 and BHP many 1911's and some fantistic plastic offerings. usually these shine at velocities below factory and run fine with soft lead. hard lead (BNH 18 - 21) at factory V do not lead my p7 or friends glocks. YMMV.

have to ask you if the leading was at the beginning of the bbl or nearer to the muzzel. think about why that would make a difference

i stock hard and get along fine with it.

[Larryect]

have to ask you if the leading was at the beginning of the bbl or nearer to the muzzel. think about why that would make a difference

I would call it more of a smear all the way down the barrel on the lands and in the grooves. I suspect to soft (and/or small) is the problem.

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[Freiheit]

Help out a rookie: Why does it matter where leading occurs?

Also, would it help to slug the bore and size exactly to the bore?

[Larryect]

Well, I'm a rookie too.

So, I am guessing - Near the chamber could be flame cutting from the powder burning up around the bullet due to too small or not enough obuturation (sp? - I think that is the term). I would guess near the muzzle would indicate excessive velocity?

What about it Claude - Am I close?

[RecoilRob]

If it only leads at the end of the barrel it can mean it is running out of lube. I guess other things could come into play too, but that can happen for sure.

I run 147's in lead 9mm after having the exact same troubles you are having Freiheit. Lyman makes a really smooth boat-tail mould that shoots great, and I can use the same lead as my other non-magnum bullets because the velocity isn't breaking 1000fps.

I have a friend that shoots 115 cast out of his High-Power but needs to really crank them out to make it function properly. This takes exactly fitted bullets and pretty hard ones too....which is too much work for my lazy self. I use heavy enough bullets to work with full power loads without driving them over 1000fps which makes them easy to make out of the same lead all the other little guns use.

[Larryect]

I use heavy enough bullets to work with full power loads without driving them over 1000fps which makes them easy to make out of the same lead all the other little guns use.

So - with soft lead, use full power (to cause the upset in the base that seals the barrel I presume?). But don't push over about 1000 fps.....


Hmm. maybe I could try a couple of tenths more powder. They are a bit lighter then the 124 they are supposed to be. Makes me a bit nervous though. Speer does list up to 4.1 gr of W231 for a 125 gr LRN bullet.

I could also chronograph them.

I still might just re-cast them and water quench to see what I come up with for hardness...

Or, just make them into 45's.....

[RecoilRob]

So - with soft lead, use full power (to cause the upset in the base that seals the barrel I presume?). But don't push over about 1000 fps.....

Yes...sort of. When you start trying to do this, you run into the conundrum of that velocity limit using light bullets for the caliber. NO WAY you can reach max pressures in the 9mm and stay under the limit unless you are using a really heavy bullet.....hence the 147's that actually weigh out to 154 lubed and ready to shoot.

The heavy cast bullets also have the advantage of being able to make a recoil operated design cycle at lower pressures than the lighter versions. Heavier is all around easier to work with than lighter...at least in my experience.

Oh...just to be clear, the lead I use is NOT that soft. Far from it. But, being WW's, range scrap and melted down commercial rejects dropped into water out of the moulds, it isn't close to Linotype and I've found the exact hardness isn't that critical so long as you give them a good boot and keep them slow. Of course, proper sizing is critical too.

Just another thought.....the OP is using a tumble-lube design with many small 'ridges' vs. the large and deep single groove of the conventional design. I always thought they would be best kept to modest velocities as the 'ridges' would seem to be prone to being 'blown out' by high pressures. The large and solid lands on the normal bullets don't seem as fussy to me. This might be totally wrong as I have never used a TL bullet, but thought I'd throw it out for thought.

[Larryect]

Since you are water quenching, it could be raising your hardness significantly.

When I have some more time, I think I will try re-melting them, water quenching and see haw hard they get.


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