Still have .40 cal leading

[ghh3rd]

I am casting 175 gr .40 cal boolits from 100% clip-on WW, in a Lee tumble lube mold, which are being used in a Lone Wolf barrel.

The boolits are dropping at about .403.

I am loading with 5.5 gr of Accur#5. This is the lightest load according to my Modern Reloading Second Edition. The 'dont exceed' limit is 6.1 gr.

I experienced substantial leading with the first boolits, which were unsized and coated with two coats of Alox.

The second batch were coated with Alox, sized to .401, and recoated with Alox. I also got leading with them, but perhaps not quite as much.

I was thinking that the boolits may not be obiturating, and that increasing the amount of powder may help. Does this sound logical?

One the other hand, perhaps I could try casting with 50% Clip/50%Stick WW to make the boolits a bit softer, and use the same 5.5 gr load of powder.

Any advice would be welcome.

[docone31]

I would go with WW Water quenched.
You are running a little soft.

[Deano]

After fighting leading in both Wolf and KKM barrels I gave up and put the factory Glock barrels back in. Poof, no more leading.

[Shiloh]

I run that boolit sized at .402 through an aftermarket barrel. The bevel base has been machined off and it drops a 158 gr. I'm not home so I can't check but IIRC, I'm getting about 860 with 6.2 gr of AA #5 clone powder.

I have the clocked info at home.

This is with Two parts range scrap, and One part WW water dropped. No leading. Accurate.

Shiloh

[Trifocals]

If the bullet you are using is a bevel base, modify the mold to get rid of the bevel base or get a different mold with a plain, flat base. Slug your barrel to get it's groove diameter. Size your bullets .001-.002 over groove diameter. Water drop or heat treat your WW bullets. Autoloaders seem to prefer harder bullets. LOL :coffee:

[sqlbullet]

I had light leading issues with that exact bullet out of my 10mm. I was loading just below the starting load of Blue Dot for 10mm. The bullets were water dropped so they were plenty hard.

Too hard it turns out. Switching to a Unique load that gave similar velocity stopped my leading. So did using air-cooled bullets.

I would try working up past the starting load and see if the leading gets better or worse.

[badgeredd]

I am casting 175 gr .40 cal boolits from 100% clip-on WW, in a Lee tumble lube mold, which are being used in a Lone Wolf barrel.

The boolits are dropping at about .403.

I am loading with 5.5 gr of Accur#5. This is the lightest load according to my Modern Reloading Second Edition. The 'dont exceed' limit is 6.1 gr.

I experienced substantial leading with the first boolits, which were unsized and coated with two coats of Alox.

The second batch were coated with Alox, sized to .401, and recoated with Alox. I also got leading with them, but perhaps not quite as much.

I was thinking that the boolits may not be obiturating, and that increasing the amount of powder may help. Does this sound logical?

One the other hand, perhaps I could try casting with 50% Clip/50%Stick WW to make the boolits a bit softer, and use the same 5.5 gr load of powder.

Any advice would be welcome.

Have you slugged your barrel?

I've found that a 50/50 mix water dropped has been very good through 2 40s. Also if your sizing .001 or more over your barrel groove diameter, the boolits should automatically seal the bore...BUT...that is only true if your casing isn't swaging the boolit to a smaller diameter when you are loading your shells. Maybe an intermediate step with a M-die will help.

BTW...the worst leading I have gotten was with HARD boolits that weren't fitting the groove diameter. They weren't fitting the bore because the case was swaging them down a bit. I used a M-die and all the problems went away.

Edd

[fredj338]

I shoot aircooled ww 40s, but I run them closer to the upper end thatn starting & leading is minimal. I lube/size though.

[jameslovesjammie]

Are you using a Lee Factory Crimp Die by chance? When I noticed I had massive lead buildup, I found that the crimp die was swaging down the bullet down to a smaller diameter. When fired, it was just skidding down the rifling instead of biting it.

I adjusted the die so it was barely making any change to the bullet and my leading drastically decreased.

[Bandit46]

I use the Lee 175 TC bullet, not the TL and cast it from 50/50 lino and range scrap alloy. It makes 14.8-15 on the brinnell scale. 4.3 of 231 in Federal cases/primers, no lead, good accuracy. These are sized to .401 and lubed in a Lyman 45 sizer with BAC red lube, and taper crimped with a lyman die.

[HammerMTB]

I use that Lee 175 TC boolit in the lube groove version. It casts .403 for me too, but I size it .401 or .4015 depending on which size die I use.
I also use a Lone Wolf bbl, but use over the max load of AA#5 by a significant amount. It pushes just short of 1000FPS.
This is in a Glock 29, so it is a 10MM with a 40S&W bbl in it.
My load of 100% WW air cooled does not lead at all. It has not leaded with loads down to 6.0 gr of AA#5.
Is your bbl rough? Have you caught a few boolits to see what they might tell you? I would start there..... :)

[243winxb]

Air cool, add 2% tin, size to .001" over groove diameter. Lyman >
While antimony is used to harden the bullet, the mixture of tin is critical, for while antimony mixes with lead in its molten state, it will not remain mixed when it solidifies. If tin were not added, we would have pure antimony crystals surrounded by pure lead. A bullet of this type , while it feels hard , would certainly lead the bore and eliminate all potential for accuracy.. In a lead-tin-antimony mixture, the antimony crystals will be present just the same, but they will be imbedded in a lead-tin mixutre. As the bullet cools the tin will form around the antimony-lead keeping your bullets from leading the bore.