peculiar fouling (leading?) issue

[jmac2112]

Hi,

I've been lurking for months now, but this is only my 7th post--please forgive if I violate some protocol! Anyway, I'm having a problem that I hope someone can help me with. First the background: I'm casting my boolits from wheel weights for .45 ACP, 9mm and .380 Auto. I powder coat with Super Durable Wet Black from Powder Buy the Pound using the shake & bake method. I get decent coverage with one coat, but if I shine a flashlight on the boolits I can see thin spots. I then size the boolits .001" over groove diameter (as determined by slugging the barrels with a soft lead slug). My loads are as follows:

.45--230 gr. boolits with 4.8 gr. Win 231
9mm--125 gr. boolits with 4.2 gr. Win 231
.380 Auto--95 gr. boolits with 2.8 gr. Win 231

I use either Winchester or CCI small pistol primers (standard, not magnum). My pistols are a Sig P220 (.45), a CZ 75B (9mm) and a Browning 1911 .380 Auto.

After I shoot the pistols, I usually run a bore snake through them to remove most of the fouling before I clean them thoroughly. After I do that, I can see that most of the barrel is pretty clean and shiny, but there is a thin smear of something left in some places. Here's the part I can't figure out: The fouling is only in the grooves at the REAR of the barrel, and only on the TOP half of the barrel (the "ceiling" of the barrel). It extends about 1" and then the rest of the barrel is clean. The fouling can't be removed by pushing wet patches using a jag, and it can't be scrubbed out using a nylon bore brush with solvent. It can be removed without too much drama using solvent and a brass brush run back and forth about 10 times. I have used a variety of solvents (Hoppes 9, Remington 40-X Bore Cleaner, and Rem Oil); they all seem equally effective.

I should point out that this is sometimes a problem with the .45, but ALWAYS occurs with the 9mm and .380. It's not a huge issue, but it puzzles me, and I hope that someone can throw some light on the situation.

Thanks in advance!

John

[6bg6ga]

Hi and welcome to the forum.

If I may ask what is your slug diameter on the 1911? and what are you sizing to?

[jmac2112]

Hi,

.3565, sized to .3575. Had to use a flex hone on the Lee sizing die to open it up a bit.

[Newboy]

I experienced a similar problem, but it was powder coating, not lead in the barrel.

It was terrible to remove. Finally had to use a steel brush to remove it.

My brass was sizing my slugs down in the seating process. I got a larger expander, and eliminated the issue.

Good luck.


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[jmac2112]

Hi,

Thanks for the reply! I have pulled a few bullets to check, and it isn't sizing them down. I'm using a cheap 1" micrometer, by the way. It seems pretty nice, however, and certainly good enough for relative measurements.

Thanks!

[OS OK]

Was the smear so thin you couldn't see it until the light hit it right? More like a discoloration of the lands? Smooth and not built up unevenly like a Pb deposit?

Might be your cure process on the PC oven. If so...verify your temperatures and start your timing after they gloss over.
I've had this happen before I figured out that you can't believe the oven dials, mine off by 75*F. Dragonheart suggested getting this one to solve the temp. problem.

Attachment 209495

[jmac2112]

Yes, it is thin and smooth, so probably PC. I have checked the temp of my oven with another thermometer and found that I had to crank it up to 450 in order to get a true 400 degrees. I have been baking for 15 minutes even though the directions say 10. I could go longer, I suppose. Is there any danger of degrading the PC by cooking longer?

[OS OK]

Watch the casts that are in the center of the mass of casts on the tray...they will gloss over last. That's when you can start the 10 minute timing.

Before I got the glass thermometer I had the mechanical one and it read too low, that allowed me to get the oven way too hot several times and turned my clear gloss coatings into a translucent looking tinted grey look. Way over cooked to the point of ridiculous...I shot them anyway in the low pressure .45ACP & .45 Colt then retrieved them. The PC had flaked off in a splotchy manner all around the drive bands on the cast...but...they didn't Pb the barrel or leave traces of PC behind.

[243winxb]

Add some linotype to the wheel weights. Try for a bhn of 15.

[runfiverun]

I would just try a different powder for the coating.

[jmac2112]

OK then, I will look into hardening my lead and/or switching powder coats, and I will double check my oven temp and bake time. Sounds like a lot of work, but the truth is I would get bored of I ran out of problems to solve. I used to be into old British motorcycles, and a poster on one of the internet groups had a signature line that read "If it doesn't need me, what good is it?" Kind of sums it up.

Thanks for all the advice!

[jimb16]

The more firearms that you use cast bullets in, the more problems you will need to solve. It is an endless challenge. And the more you learn, the more you will realize that you don't know. I've been shooting cast for 45+ years and know less now than when I started!